My wife have this exact problem on Mi10T pro on vanilla Miui global so it's probably not xiaomi.eu problem but I also would know what is causing this.I have an issue on my Poco F3 Phone:
Always when i want to call somebody, i can't hear them, but they can hear myself. I must close call and recall him, than it works. Every 8 hours 1 time.
Do you have an idea?