Emptying Trash not emptying over Wifi

I’ve been having this issue for a few weeks now.
When emptying trash from the deleted folder while on wifi, emails aren’t removed from the Deleted folder.
As soon as I turn off wifi, those emails disappear, without having to click Empty Trash again.
I have to do this about 95% of the time when emptying trash.

I have no other issues with anything over wifi, just this.

Yes, I’ve restared the modem just to be sure. Same problem.

Please help

A log would probably help, and which K-9 version you are on.
I’m on 6.400, always on wifi and my Trash empties just fine (I just tried it again to be sure), so it would have to be something device or rom specific I guess?

Thanks for the reply.
I wasn’t sure if others were experiencing a similar issue, or not.
Running 6.400 here, but it happened on the previous version too.
Wondering if it could possibly be a server connection issue (for me specifically) when emptying trash over wifi as opposed to data.
I’m tending to lean against it being device specific, only on the assumption I have no other issues with my Samsung S20 Ultra. But I’m not ignorant enough to rule that out 100% either.
I’ll clear the cache again and see how it goes for the next few days