We recently updated our server to 2020.4 and noticed that we are not getting issues with writing to an excel path from server.
It seems that files keep getting corrupted; I have no clue why this is happening and if there's a work around. But these are brand new files getting written to new workbooks.
We were working on 2019.4 before and had no issues until we did this migration. Designer works fine and server desktop works fine as well. The issue is really when the task is being completed on the gallery.