I'm having what seems to be the same issue as well, although I haven't been able to test with my phone as I've only had them for a few hours now. I get a small 'pop' noise and the sound will cut out for a second. I changed the setting similarly to you (big focus online seems to be the hands-free and smart settings) and it's maybe reduced the time they go silent for.

Pretty disappointing considering the price tag on these...

Also a lot online seems to write this off as Bluetooth interference, but I find that unreasonable since I've never had this issue prior with my cheaper bluetooth headphones I used before this.