[Edit by @Stefan: This post was moved from that topic.]
I’ve got a similar issue, however it happened 2 weeks or so after Kola nut was installed on my phone (not straight after). My phone is unusable as a result.
Other users have experienced the issue before the update was released, others have reported it as a result of updating from 1.3 to 1.6, whilst with other users the issue seems to be independent of the updates. There’s been lots of posts describing the issue as associated with charging, although there are also cases of the issue occuring when the phone is not charging, or being held on its metallic case.
See topics titled:
“Buttons pressed randomly”
“Touch screen activating by itself”
“Phone goes crazy - gets inputs I don’t make”
“Touchscreen detecting inexistent touches”
"Software update Cherry 1.6"
“Lower area of touch-screen not registering press”
“Capacitive buttons and lower part of touch screen not reacting”
“Random key action”
“Fairphone got a mind of its own”
“Several Problems with phone”
I have made a list of all users I could find who have reported similar issues on the forum: 30 individuals, and this excludes users who may have directly contacted support. That’s a failure rate of 1 in 2000 (assuming both batches). I’m slightly regretting having purchased the phone to be honest; I’ve been keeping off from buying a new phone since March last year, persevered 6 months with an old and tired phone until I got my FP, and it does that in three months with no impropper use.
I reported the issue 5 days ago and the only response I’ve had so far is whether I’ve installed Kola Nut.
What surprises me is that not many (I’ve only seen @humorkritik post a post-repair update) of the people reporting issues have actually provided any information on how their problems got resolved (i.e. repair, replacement, warranty, how long it took them to get a functioning phone back).