iPhone continually clicks and turns down volume to zero on calls and teams meetings

I have a jabra evolve 2 75 headset connected to my iphone through bluetooth.

After upgrading to IOS 17.6(*), the phone acts weird when using the phone or teams app, while the the DS audio app works just fine.

I have not checked all apps, but this leads me to believe it is an IOS issue and not a headset issue.

Once an audio connection is active, I hear repeated clicks in the headset, and for each tick, the volume is turned down, until it reaches zero.

I can use the volume buttons on the side of the phone to turn the volume up, but the clicks continue to appear, so i would have to do this constantly to keep the volume up.

I have tried (unordered list):

• Restarting the iphone
• forgetting the headset and repairing
• Unpaired headset from all other devices
• updating the headset to latest firmware
• Ensured the automated sound reduction of headphones is turned off (Settings-Sound/haptic feedback- Secure use of headphones)
• Ensured work focus is disabled (settings - Focus - Work - smart activation)

Does anybody have an idea what is going on?

(*) it might not have been caused by the 17.6 update, but I did not notice this behaviour before that.