Capture one pro unstable when loading catalogs

P1C1 21. Went through and loaded catalogs and upgraded them to current db version when necessary and all seemed OK. None were loaded into a new window. After doing the last one, I reloaded one just previously loaded (PCH) and the application half drew the interface then got stupid, endless spinning cursor and no menus functional. Task manager showed P1C1 using ~5% cpu, approx 40GB of RAM, .1MB/sec disk and no GPU. I watched it for a few minutes and the memory got as far as 58GB when I killed it.

P1C1 14.0.1.5.a37c5ee.f00ed76, win10pro v2004 19041.630. dual proc Xeon e5-2678v3, gtx1080 driver 457.30, 64GB RAM. Catalogs are stored on an SSD, r/w approx 450 MB/s using BMD disk test. Images on NVME PCIe. I cant open the PCH catalog without a hang, though others will load. PCH has about 8000 images in it, mixed nef and jpg, others smaller.  When loading it never shows any db errors, just hangs. Verify shows no errors. Previous version was 20, latest release. Had something else to do and left it "loading" and it actually did, although it took 7 or so minutes of looking like it crashed. Awesome. Any thoughts?