[OS X TeX] Weird issue when upgrading to Monterey

[juan tolosa]

Hi,

After some trepidation, I upgraded my oldish Mac book pro (2015) to Monterey, and then a weird issue appeared.

If I try to open a .tex file residing in OneDrive which was not created, say, in the last couple of days, then it shows up as blank, although the “get info” menu reports information is there. When I try to open the same file, also from OneDrive, but using the PC instead (and PC TeX) then the file shows up fine. 
Also, if I try to open the corresponding .pdf file, then Adobe Acrobat complains if I am on the Mac, and shows the .pdf file fine if I use the PC instead.

On the other hand, I have no problems opening a .tex file that resides in the Mac book itself, instead of OneDrive.

Has anyone encountered a similar problem?
Any advice would be appreciated.

Confused,
Juan