WP2021Problem printing labels

I recently upgraded from WP2020 Home to WP2021Standard (ver 21.0.0.194) on a W10 Pro computer with latest upgrades. I am having trouble printing labels using WP2021.

When I select Format, Labels, Avery 8160 English, the labels come up looking proper on the screen. Then go to Print, Properties. This shows the Paper Source as CD/DVD Tray and the Document size as A4 (see left side attached screenshot). I change those properties to Cassette 2 and Letter (see middle of attached screenshot). Go back and click Print. An error message appears “The document page size is set to a custom form that may not be supported...” and the printer has to be reset. Nothing is printed.

This W10 Pro computer prints other documents as expected.

Another W10 computer with WP2020 Home prints labels to this same printer as one would expect.

I have tried (1) printing other Avery labels and (2) printing other brand labels. No success.

I have uninstalled WP2020 Standard, deleted all WP program files I could find. Rebooted the computer and re-installed WP2020 Standard. Labels still will not print.

Any suggestions anyone?