I was installing NTFS for Mac and then I started getting told to give it full disk access.
It's pretty bizarre Paragon would tell you that. The installed driver already gives you read/write access to an NTFS formatted drive. You shouldn't need to do anything else.
Well, not unless changes to macOS over the years causes the OS to treat a normally unsupported format with suspicion, and you have to tell the OS it's okay to access it. Which is still weird since even without the drivers, you can still read an NTFS volume. Or, you're supposed to be able to.
Before I installed NTFS for Mac, I was able to read-write to an external drive. Now it won't show up as a location on a finder window.
I haven't payed a lot of attention to NTFS lately (like the past few years), but I have seen a few other recent topics here where users are having trouble accessing an NTFS drive in Sonoma and Sequoia.
It is now read-only. And it looks like everything I had on it is gone.
That's certainly not good. I can't test it either since the last drive I owned with NTFS was reformatted to ExFAT.
The data is likely still there, but macOS isn't reading the NTFS format properly. If you remove the Paragon drivers and restart, can you then see the files on the NTFS drive?
If so, I would strongly recommend to stop using NTFS. If you have it formatted that way because it's a drive you move between Windows and Mac computers, copy everything off to either computer, reformat the drive as ExFAT and then copy everything back.
Both systems can read/write ExFAT without the need for any special drivers.