Cannot change volume when streaming to Kodi via bluetooth

Hi

I just picked up a Vero 4k and connected my iPhone via bluetooth to play some music. My amplifier is connected via 3.5mm jack. Audio plays fine. My problem is that I am unable to adjust volume through the controls on the phone. If I adjust volume to 0 % then the playback is muted, but anything apart from 0 % is just playing at 100% volume.
Perhaps I am missing a setting? I just use the My OSMC interface to set up the bluetooth connection.

Br Eskild

Unfortunately this is a limitation on iPhone.

I can reproduce this on iPhone 12 Pro.

You will need to use the AVR remote.