Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hi,
If you are still having this issue I may have a solution. We had this issue with our engineering department and turns out that the reason Adobe wasn't able to open the files directly from SharePoint was that the file names had too many characters/too long. We figured it out when some files were opening and others weren't in the same file library and the ones opening had shorter names. I shortened the names of the files that were not opening and it worked immediately.
Hope this helps!