Xiaomi Mi Mix2S - no sound with USB-C headphones

Hi,

my USB-C Headphones worked on my Xiaomi Mi Mix2S with stock Androind and MIUI. Since I use /e/ Q the headphones are “dead”. There’s no sound. The headphones are recognized by the phone, there’s the symbol (next to the WiFi).
I’m on /e/ Q - do you think upgrading to /e/ R will solve this problem? Or is there any other solution to this problem?

Thanks