I wanted to put an update on this after few weeks. I am now to a point I have installed a fair amount of apps and suddenly the problem started occurring again, apps in the background being killed. Not sure when it started, and if its the amount of apps, I have no idea but Im pretty bummed. Its still not as severe as before, but still.
I must say the battery problems are still terrible.
So the factory reset isnt a 100% solve.
Thanks for the news.
I confess that I would have expected this. Don’t forget that an app can be using resources in the background even if you haven’t seen it in the foreground or launched it yourself, for weeks.
When faced with this type of problem, and while waiting for the fix, my advice would be to limit the number of apps installed to the minimum you can get through the day with. You might try removing the most recently installed apps.
Its fixed with this update
Hello
Update just applied.
For now, I would say it’s better, but maybe it’s because of the reboot.
I will get back to you tomorrow after some more usage of my phone, especially with a little run with music and tracking cardio/map app etc.
Curious to see if battery goes better without the need of restarting apps too often.
Finally! At first glance, the fix lives up to its promise. 
VPN, browser, banking, baby phone, … – no killing yet! 
At long last. So far, it seems to work quite well and has resolved the issue. If something comes up in the next few weeks or so, I’ll circle back here. But thank you for the heads up.
To be honnest, it seems really, really better.
I think I can say the issue has now been solved !
So I bought a new battery, as mine as 3 years and, to me, this issue just drained the battery faster than it should, but well, I should have needed to change it one day …
Is it ok for you too here ?
Even if it took really too long to be addressed (fairphone I love you but you should really spend time and money to resolve this bug addressing problem), thank you very much for solving it !
Dear community,
For a few months now, with my FP4, music apps (radio and Spotify) randomly stop when opening other apps and sometimes when the phone is only playing music.
I tried reinstalling the apps but this didn’t fix the issue.
Anyone experienced similar situations and how did you fix it?
Hi and welcome, moved your post here. Please confirm the software version you have installed. 2 days ago the fix was released
After a few days I’ll cautiously declare that the issue seems to be fixed for me. It’s great to finally have a phone that can do multitasking again! 
Hi
It seems to be solved. I’ll have to test for few more days to be sure but so far, so good
Thanks for fixing this really annoying issue. I know Fairphone has been working on this since the problem appeared. It was hard to stay positive when your phone is barely usable for months. But the most important is that a solution was found and released
Thanks for the work and not letting us down
I received the update yesterday and installed it asap. I see much improvement. Apps are far less being killed! So happy!
I suppose Orange is slow as usual to distribute this patch?
I’m with Orange France, and I don’t see the update either.
I’m with Orange France too, and the patch appeared last Saturday (June 6th), so YMMV: I already did see updates which were “not for Orange users”, and only my mistrust saved me from installing them. Maybe it’s because I also have a Vodafone Germany SIM, but that one has its data switched off, so I’d assume it can’t poll for updates.
Yes that happens to me too with music and podcast apps. I’m installing the new June update hoping that it fixes all memory issues.