Well, same here. I am quite sure I tried everything in order.
But just to be sure I will retell my try here, maybe someone notices an error.
- I tried flashing the TWRP with OTA Fix as it can be found in this thread via
fastboot. This attempt failed, as the screen turns blue when booting into recovery, but the phone is recognized via MTP. - I tried flashing a TWRP without this Fix, directly downloaded at TWRP Project website. Same result.
- I learned that Open Source FairphoneOS is delivered with TWRP preinstalled. Its Version is older (3.0.2-0 instead of 3.1.1-0 from point 2), but works like a charm. So I flashed the Open Source FairphoneOS, which works.
- I tried flashing LineageOS for FP2 as described in this thread using the TWRP I flashed at point 3. Trying to boot the flashed LineageOS also ends up with that blue screen from points 1&2.
So I finally decided to stay with OpenSource FairphoneOS because I am in control of my device then and can make a living without Googles “Services”. But I would like LineageOS 14.1 to run on my device, because I started to like it on my tablet. Maybe someday, someone has an idea about this. Maybe I forgot to make a vital step while flashing, I have no idea…
But anyway: Thanks for your investigation @Roboe 