Maybe that’s an option for new topics (where a related topic can now be quickly found thanks to your list 
) or in this specific case, but not for the whole backlog.
Let’s have a look at Call quality and noise cancellation, these are similar topics I found, just skimming the list of topics, that could be related:
- Call Microphone Issues?
- Fairphone 4 - What is wrong with this thing?
- High-pitched screeching sounds when making calls and problems with usb-c adapter
- Hatched sound durings phone calls
- Microphone cutting out
Similarly for Microphone quality of the FP4 when using Signal (low volume), these could be related as well:
- Voice recording is broken after new software update
- FP4 external microphone volume and equalizer
- FP4. Microphone not working when recording
Arguably Call quality and noise cancellation and Microphone quality of the FP4 when using Signal (low volume) might even be related as well…
I don’t think it’s feasible to merge all those topics. It’s maybe justifiable for some of them, but others seem to only share the general underlying problem with different symptoms.
Without knowing the exact cause of those issues, attribution quickly becomes hard.
I have no idea how to solve this easily, I mostly wanted to start a discussion before I add things to the list that aren’t welcome there 