XMP Files Gone (even with save xmp box checked)

It seems as though "Saving XMP was paused".  I have no idea how that has been on for the last few months.  Seems like an idiotic feature.  Thanks to Aleke for your answer.

And to the makers of Lightroom, why on gods grean earth would you put that in there and not make it obvious?  I have lost a good months worth of editing due to this dumb feature.  I had manually archived everything, always have, always will but my ability to adjust what I had adjusted is wiped out.  Lesson;  don't ever trust any of the "features" in Adobe software.  Do your own backup.  I've had this stance since I attended the unvailing of photoshop some 30 years ago and it's almost always paid off.

Lightroom hasn't been saving my xmp files, even though box is checked.

Do you mean Lightroom Classic? What is the evidence you see that makes you say this isn't working? Please show us a screen capture of the checked box and another screen capture of what you see that makes you say .xmp files are not being created. Use the "Insert Photos" icon to include your screen captures in your reply. Do NOT attach files.

I import cr2 files, edit them and archive them.

How do you archive them? Please provide details, step-by-step, leaving nothing out. Is the lack of xmp files that you are complaining about before your archive them, or after you archive them, or both?

I have way too many files to keep them in the catalog, they have to be archived.

I think a lot of people would advise against this. There is no such thing as too many files in a catalog, and virtually no drawbacks to having a large catalog (EXCEPTION: making catalog backups take longer with large catalogs)