Clearing the cache does not fix anything on my phone (same build as you). Some users say they are not affected, I just wonder why.
This fixed the issue for me, but just for one day.
It’s back to normal (response time anywhere between 5 and 10 seconds) now 
Seems fixed now with A16. What about you ?
Indeed. I’m currently running firmware FP6.QREL.16.61.0 (Android Security Update 2026-04-01).
And I’ve tried to reproduce the issue again this week (2026-05-21, KW 21) and it seems fixed.
“seems” because there was always some randomness to it. But I’ve tried it several times this week and I’m quite convinced it’s gone. It might have been the firmware update, or the latest version of the com.fairphone.settings.switchbutton app (currently version 4).
I also had a Fairphone Support conversation. And the support employee also mentioned that this was fixed by a recent update.