Volumio controls stopped working fully

Volumio Information

Volumio Version: 2.748
Hardware: Khadas VIM3L
DAC: Khadas Toneboard

Hi, I set up a new Volumio/Khadas streamer a few months ago, and have been really impressed with the sound quality. I’m mainly streaming music via Tidal.
Recently (probably over a month ago now) I lost a lot of the functionality of the Volumio Web interface. The play button to play a whole album doesn’t work. The play button for individual tracks doesn’t work. The only way I can now listen to tracks is to click ‘clear and play’ for one track at a time. The queue doesn’t work at all, and I’ve also lost use of the volume control.
Please let me know if anyone knows what’s going on - I haven’t changed anything that I’m aware of.
Thanks, Richard