I am not sure if my ghost touches have vanished after the update, I saw a glimpse of them but not enough to conclude it is the ghost touches again.
But I did experience a new phenomenon. Sitting outside a restaurant under a giant sunshade the display brightness dimmed down to an unreadble setting and I had to move the phone into a bright spot to make it light up the screen and then I switched off automatic brightness.
Weird, I have never had that effect before the update… I know that scientifically speaking this is no evidence of course, just coincidence maybe…
So you are saying the brigthness slider moved down actually?
Yes, it did. Then I switched off the “A” and moved it up manually.
Interesting. It doesn’t do this on mine:
In my hand it’s like before the update. Lying on a (wooden) table, no touching except the screen, it works just the same too. No difference I could see.
(Both test made with Google Maps. I’ve never experienced ghost touches. Phone is almost a year old, heavy use.)
Disclaimer: It’s hot and humid right now, this might have something to do with it, I guess those are the ideal conditions for the FP4’s touchscreen.
I know that my FP4’s screen is affected by temperature (it’s much less sensitive in cold: Back in winter, while outside (around 2-5°C), the screen became quite unresponsive. Not to the point of being unusable, but definitely annoying), and since finger touches are registered by capacitance, humidity would probably change their response too (guessing).
------ EDIT:
No, error, actually I do have the same effect (less responsive when lying on the table). I had forgot to unplug the charging cable! The charging cable did the “holding hand” effect…
So yes, you seem definitely onto something here. And for those who use it in their car, plug it in, that should restore touch screen sensitivity.
------ EDIT again:
Apparently there is even simpler: Just plug a USB cable into the phone, doesn’t need to actually be connected to anything! I tested it by just plugging the official USB-C to mini audio jack adapter, with nothing plugged in it!
Despite its only 10 cm length, it was enough to restore touch sensitivity, so it doesn’t need much.
(Also posted further down, but I thought I’d assemble everything here)
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probably a bit more patience to breath and check and see what is reported helps. Yasen proofed multiple times he will be back when he has some information and not everyone need to ping him over and over again thats just spamming his mailbox and increasing the chance to loose track.
Edit#: who wants to discuss this further, please do it here to keep the topic update topic as clean as possible
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Since my first comment got split out I want to mention again that scrolling smoothness is also affected. It’s a bit like scrolling with a mouse wheel where it snaps to the ratchet but the hitching is more subtle. I suspect most people won’t consciously notice it but it’s a big papercut that gives an impression of a sluggish, underpowered phone. This effect is more pronounced when lightly touching, on a desk, etc. so it’s probably related to the same set of changes.
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Thank you for your suggestion with the charging cable, I could reproduce that here. Leaving the phone plugged in when in a car may not be a solution, but for me it is certainly an acceptable workaround.
P.s., I love the suggestion that we have to hold hands with our phones so they are more sensitive, that’s so cute 
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I just tried to zoom in a map while the phone was in the car mount and I had to touch it somewhere at the back or side to make it work. A third finger of the same hand was sufficient.
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Thank you for this thread. I thought I was going crazy, pressing my screen trying to get it to respond! Seems I have the issue of the screen being less responsive when it’s flat but fine when held upright. I got a screen protector a few days before the update but was fine until I updated.
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Hi all,
I just wanted to thank you for the detailed feedback about the touch sensitivity after the update. There’s already an internal bug report about this and it will be treated with a high priority. I will periodically monitor this topic and forward relevant feedback to the team.
Please be mindful that we’ll need time to investigate why the display reacts differently, depending on how it’s placed and whether it’s charging. After we have a better understanding of these factors, we’ll have to adjust the calibration and make sure it doesn’t have any other unintended consequences. We are still at the start of this process and there is a lot going on in the background (including a certain Android upgrade) so don’t expect it to be fixed in the next update.
I’ll let you know when there’s a clearer ETA.
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Caveat, totally wild guess, I’m not an electronics engineer, touchscreens are AFAIK a whole science on their own, and we don’t know how the FP4’s one works anyway (there are several methods).
All we know is that there is some empirical evidence that the FP4’s touchscreen now requires the phone to be connected to some larger conductive body to reliably work – Either the user also touching the phone’s chassis, or the phone being connected to something else by its USB cable (like while charging it).
Could it be the update lowered the gain of the capacitive touchscreen so much, it now requires some kind of grounding to reliably create any detectable change on the screen’s electrostatic field?
In which case it should be simple to raise the gain back again, just enough to make this annoying side effect disappear (don’t know what this would do to the ghost touches issue though…).
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I have exactly the same problem, but only when the phone is on the table, for example. As soon as I pick it up, it works.
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After the update the screen works normally, even when unplugged on the table.
I don’t have a protective glass foil, do people with the new issue have protective foils?
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I use the official screen protector by Fairphone. I have the issue when its flat on a table and trying to pinch to zoom. Then the multi toch isn’t registered. You are testing zooming? Just to make sure we’re testing the same thing. There are some other issues as well, but the one on a flat surface is reproducible and thus a great reference point.
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Just tried it myself and put the FP4 on a table and used it like normal with one or two fingers. I don’t notice any issues with tapping, swiping or zooming. I don’t use any screen protectors or cases.
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Flat on the table, testing both rotating and pinch to zoom. Works as expected 95% of the time. Sometimes effectively seem to have trouble to immediately register the rotation after zooming, without taking away the finger. If you remove the finger and touch again then you can rotate normally.
As I said, no screen protector.
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I use a BROTECT AirGlass Matte Glass Screen Protector.
Tapping and swiping is good. If hold the phone in my hand no problems with zooming or typing.
But zooming or typing is not working when the phone is flat on the table.
As I never use the phone flat on the table, I don’t know if I could before the update.
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