Me too. I have an iPhone 7 with iOS 13.1.2 and Plantronics Voyager Focus UC (B625) Headset.
The Headset is double-paired with my iPhone and work PC. On the phone I listen to Music and Podcasts, on the work PC i do VoIP calls.
Since iOS 13, the volume on the phone gets muted whenever i pause for a few seconds or take off the headset. I then have to turn up the volume manually, else it stays muted on resumed playback. The phone mutes the headphones every few seconds when no audio is being streamed, which manifests in a bluetooth volume bar notification on the left.
About once a week, the iPhone's Ringtone gets boosted to maximum, though i have it muted at all times.
Worst of all however is that the bluetooth connection gets dropped while streaming audio from the phone and i get a call on the PC. It just drops the connection to both the iPhone and PC. The headset then reconnects, first to the phone then to the PC, but this takes so long that i often miss the calls.
This happened in iOS 11 and 12 as well, but only once per week. Now there's a 50-75% chance with every call.