Call volume strong fluctuations with headphones

[jrzenfone8]

Hi Asus, when using headphones for calls, from time to time audio will fluctuate either becoming too loud or too weak. Makes it difficult to use headphones.
I've noticed it with or without outdoor mode, happens on every call.
It does not happen: without headphones (whether hands free or ear speaker), nor with music - only during calls.
Could you please check? Thanks

[Gustav_ASUS]

jrsenfone8 Which kind of headphones, wired or bluetooth? Does it happen with both?

[jrzenfone8]

Hi sorry I was so happy to have a top spec compact phone with an audio jack that I forgot to mention it. Wired headphones. I don't have Bluetooth headphones so I can't test it that way.

[pipsss81]

It fluctuates over speaker, so it makes sense it does it over audio jack also. I assume it uses same DAC. Some said it is an android issue, so they probably just wait for new android version.