strange export behaviour (can't export csv but other file types work well)

I came across a rather strange problem in paraview. There is probably not much help here that I can get for this particular problem, but maybe someone has some idea how I can debug this problem.

I am currently not able anymore to write csv files from line plots to some parts of my hard disk. Some folders are OK and I can export data there, but others (the majority) are not. These folders are not read only, I can create new files and folders there. In-fact, if I try to export my data as any other data format (say cgns or vtk), I am able to export my data from paraview to these folders, where the csv export fails. I have tried both v5.8.1 and v5.8.0 and I have run paraview as an admin, both did not change the outcome. As a work around I can save the data to some inconvenient temp location and then move the data, but I have a lot of data and macros for automaticaly extracting and exporting data to the right folder, so I would really rather understand what the problem here is. I don’t get any error message, i.e. after I export the csv file it seems to have worked but it is just not created.

I am using win 10. It was working fine a day ago or so and the only change I made to my PC was to install an unrelated software (VM Horizon Client). It might have affected things but I can’t see how.
Any suggestions on how to debug this problem would be welcome.

That sounds a lot like the infamous \U issue we had on windows. It has been fixed already so it is not the same.

Are you able to save anywhere but in C:\Users* ?