Hi AmberNowak,
Sorry for the inconvenience the problem caused for you.
Based on your description, the file can't be uploaded completely to the Teams Assignments. I tested on my side, I can upload files successfully.
To help you better, could you please provide more details for me?
- You can try to upload files from Teams Online to check the result.
- Does the problem happen on all your Teams group, or the specific group?
- Can you upload the files to the SharePoint site related to this group? Go to General channel > click "…" on the upper-right corner > click "Open in SharePoint" > go to "Site contents" > Class Files > Assignments > select the problematic assignment > upload file.
Additionally, could you please provide your account for me via Private Message to check the Service Health?
Appreciate your cooperation in advance.
Best regards,
Jazlyn