Hello! I encountered an issue with submitting my assignments on MS Teams. Unfortunately, I cannot turn in/submit my assignments because the 'Done' button is grayed out. I also tried this on MS Teams browser, yet I still encountered the same problem.

What happened was,
(1) I uploaded two docx files, like what I normally do, then turned in my assignments. However, I suddenly had to change something on the file I submitted so I had to undo turned in.
(2) After editing the documents, I uploaded and turned in the second version of the files. However, I missed an error on the documents and I had to undo turned in again.
(3) When I was uploading the third version of the files, I noticed an additional number in the file names, and I was bothered with it so I go to our team's SharePoint and deleted the old versions of the files (Site contents > Student work > Working files).
(4) Then, as I was uploading the final—revised version files, the 'Done' button became grayed out and I wasn't able to turn in my assignments in our teams.
How can I fix this problem and may I know the reason behind this issue? Thank you.