All msgs disappeared from Google SENT box. New msgs are there.

Platform : 13”  MBP 2020 M1 Sonoma 

Mail on Mac 16.0

Two mail providers. Local and Google.

All contents in Google SENT mailbox (ca 40 msgs) suddenly disappeared and box empty.

New test msgs I sent after the event appear in box, but previous 40 gone.

They are not in TRASH, ARCHIVE, RECEIPTS, JUNK, WORK & IMPORTANT etc

Some (all ?) seem to be in ALL MAIL, mixed with incoming msgs.

How/where can I find the lost 40 SENT messages lumped together?

Many thanks