Unified view of Yahoo Mail Trash - They un-check themselves

[sludge7071-g]

I'm using the latest, TB 60.5.3

I have 6 GMails and 2 Yahoo Mails

Unified View / Trash / Properties

I click "Choose" / I [check] all 8 Trash / Update

It appears to work fine.

I close and re-open TB, and see that TB has un-checked one, or both, of the 2 Yahoo Mail Trash.

Any idea why it does this, or how to fix?