Printer Malfunction in Catalina

My Samsung Xpress M2830DW laser printer has functioned perfectly for years through a succession of iMacs and macOSes. I was concerned that its driver(s) were not new enough to be compatible with macOS 10.15, so I waited until 10.15.1 came out and reset the Samsung as an AirPrint printer before upgrading from Mojave, following advice to get around any 32 bit issues that way in lieu of being sure I had 64-bit drivers. Mistake. I should have stayed with Mojave.

The Samsung now functions perfectly via AirPrint when other Macs and iOS devices running the latest version of macOS or iOS/iPadOS in my home print to it, but it behaves strangely when I try to print to it from my main desktop iMac running 10.15.1. Here's what happens: If I want to print an email or web page or document I've created, I hit Command P and it will start printing an unstoppable number of pages with one or more lines of ASCII text and will keep printing until I turn off the printer.

Sometimes, it will print correctly if instead of using Command P I click on a printer icon in the document. But if I try to print the same document again that way, it starts spewing out endless pages of 1-3 line ASCII gibberish.

I've tried deleting any and all Samsung software, booting in Safe Mode, doing a PRAM reset, resetting the printer system via System Preferences, etc. Nothing works for more than one correct print session (if I'm lucky). It sometimes will print correctly the first time if I hit Command P, but will revert to the ASCII stuff on second printings.

I've tried installing the latest drivers (from HP since it bought Samsung's printer business), to no avail. Either the latest drivers aren't 64-bit or that's not the problem.

I also have a Brother HL-3180CDW on my local network, and it performs perfectly as an AirPrint printer, no matter how I choose to print a document.

The Samsung responds properly when I switch to a backup user account on my iMac. So the issue appears to be related to my main user account and something that happened when I upgraded (?) to Catalina. There have been a number of niggling to major issues caused by Catalina, from a complete trashing of my Time Machine backup to Moonlight Mahjong not working right and now to this Samsung printer ASCII fiasco.

Aside to Tim Cook: I'm getting tired of going through this kind of BS every year in the service of newer is better and change for the sake of change.

Help!