Summary workaround:
Go to settings via the quick settings menu (pull down from top and select the gear icon-select apps-select Playstore-open it using the small square at the top right-download another launcher (e.g. Fossify)-open it and select it as default
I like the look more actually… however the important thing at the moment is, you can use your phone.
Now def back up all important data when you are not doing this on a regular basis and report to support as long as Fairphone didnt confim to have logged the bug internally…
Edit: there is a second woraround, requiring a PC and adb
I know its no solution ,still I will mark this post with the a workaround as solution for this topic so that people can easily find it.