"Your message couldn't be saved because the attachment is still being edited" message

I have an environment with Exchange 2019 servers and Office online Server.
I'm able to open an Office document directly in Outlook Web Access and can open and edit the document.
After editing and finishing the document I see the status changing to saved.
when I try to send the email with Office document OWA tries to close the attachement and send the email, but after a short while this message appears and the email can't be send: "Your message couldn't be saved because the attachment is still being edited".
When I click Ok I can see myself twice editing the same document.

When I click Ok again I can see myself three times editing the same document.

It seems that there is something going wrong with closing the Office document.
Any idea how to solve this?

Office Online server edititing issue.jpg
Office Online server edititing issue2.jpg