On my non-WiiM A10 mk2 TuneIn radio works fine, there's also a general 'Internet Radio' function which has all the BBC radio stations. These can't however be added to the preset buttons on top of the speaker - they show as presets but pressing the button does nothing. It's been acknowledged by AudioPro and a quick google shows it's been an issue (maybe consistently) for the last few years but no fix is apparent.
My Ultra and Mini however both have the separate BBC Radio app which allows me to have a preset assigned to (for example) BBC Radio 6 Music or Radio 4.
This was the main reason why I bought the A10, I'm only keeping hold of it because the Spotify and Tidal connect functions seem to work well (and it can be paired with the Mini or Ultra).