Hi - I just saw this response so I apologize for the late answer on my part.
I am still not sure I understand what is going on. It could be something with an upgrade either to Lightroom or to DxO which happened around Jan 15.
My suggestion for now would be to open the catalog that is working, Catalog 3-2?
Then go to File > Import from another catalogas in the image below.
Then direct the import section to the old catalog (Catalog -3) and see if you can import everything.
Next. I would quit Lightroom, then restart it and see if everything in Catalog 3-2 in now in place with all. your previous images and all their previous edits.
There is some information on the Adobe help site regarding plug ins and problems:
If everything is completely copied over and you again test it with an import from DxO, then maybe it was just a glitch. And. then you can remove the old catalog, rename the new catalog 3-2 if you wish.