As above really, my front ring is making a kind of soft brushing noise. Sound as if something is wrong but no effect on riding, just an odd noise.

Any suggestions on what to check?

Probably being dragged across due to the chain line. If you put the bike upside down and back pedal slowly you can see the teeth meshing and watch how the chain gets dragged down the tooth into position.

Thx Andy will check. Shifting to the bigger front ring is also a bit odd – could be related?