I've been unable to sync my XMR wallets since a few releases back. The sync icon turns to a red X and that's that.

Since a version or two ago it sometimes turns to yellow again but then red again, and that's that. Seems to happen if app is in the bg and/or shortly screen turns off.

It's made it all but unusable, which is a shame, I like the UI.

Is this a known problem?