Attendance report missing, not available for download

Question

On 28 Feb I conducted a training via Teams. So as usual I'll easily retrieve the attendance report from the download section. Unfortunately, this time, the following prompted when I tried to retrieve it.

I waited and tried to download many times but failed. Then I entered the session again to see if that'll lead to anything. Surprisingly, my short entrance was recorded instead. As shown here, no previous attendance available at the drop down. So now, how can I retrieve the original session's attendance that has gone missing?

Thank you!