Moved all emails of different accounts to trash folder

I am using Version 5.807 k-9 Mail Android.
I am using 4 different email-accounts within application
When starting k-9 this morning on all 4 accounts all emaiis in inbox have vanished. Later I found all emails in the respective trash folder ----- why and who had moved all emails to the trash???

When i tried to remove the emails from trash to inbox I only get the message messages , which haven’t been synchronized with the server cannot be copied or moved (please note I am running K9 in German, so I tried best to translate)

Who can help me and how can I avoid that hundreds of emails in the 4 accounts have to be moved manually piece by piece… :frowning:

I am using k9 since many years fully satisfied, but thanks god I have thunderbird on my notebook so I have a full backup