How confident are you the actual headphones microphone is being used?
Often with Bluetooth with computers the headphone profile is being used so you use the headphones for sound out (what you hear) and the built-in microphone for input (mix).
Check your mic used is the headphones and not the built-in mic.
Test is to when in calls tap the headphones, tap the computer, see where is loudest
A search implies there’s no fix for this because if you switch to the headphones for mic the audio quality is worse. Scrolls through the search bearing in mind don’t focus on your specific soundcore product but rather the fact it’s Bluetooth and a Mac.
When you did your research prior to purchase did you find out this issue with Bluetooth and Mac and if so why did you pick the Q20+ specifically? There’s ooodles of existing threads around Mac, PC, Bluetooth issues, nothing to do with a specific audio product. Most people either own an inline mic cable (Q35 comes with one, does the Q20+ ?) or just accept the Mac / PC mic is being used, and know this prior to our purchase as they researched and knew already.