For me restarting has zero effect and this has been going on pretty much since I got the phone early this year 
Just to ensure we do not duplicate discussion, I moved your posts
Thanks @yvmuell for consolidating them!
Quick update I do now have a ticket and emails from the support team but we are starting at “have you accidentally turned on airpplane mode/have you switched it off and on again”.
Unfortunately all the detail I put in the chat does not get passed to the support person so I have to do it all again as there was no way to save the chat text. As an engineer myself I have done quite a lot of testing and diagnosis and small fixes like updating software before I ask for help. I get that this is unusual, but it would be helpful, faster and improve our customer support experience if the stuff we send to the AI/support team in the chat was transferred when a ticket is raised.
A note for the future, Fairphone support designers!
After a long list of things to try (none of which work)last week, support have gone silent for the moment. So, two questions to anyone reading this- what was the last, reliable Fairphone model if there is one, that will be supported for a couple of years further? It seems like the FP5 may also have issues.
Otherwise I think I am going to have to abandon the brand if there is a designed in flaw (I mean as a result of the original design so a significant % of units fail and repairs will not fix, not a deliberate fault here) in the FP6 and no older sensible alternative as may be the case, looking at the community forums posts. Th only issue with the FP3+ I had to get rid of was the discontinued support and it’s brain simply not being big and fast enough for modern apps…