I use a Dymo LabelWriter 300, and in upgrading from Linux Mint 19.whatever to 21.3 I found everything moved just right and the label printer prints from gLabels.... but much smaller. I checked the label size- it's correct; I don't know what else to change. It's as if it were set for a smaller label size- MUCH smaller. The labels appear the same as always on the screen; Page Setup has scale at 100%. The Preview comes up right- everything is normal.

Printer properties are correct- scaling at 100% there, too. Printing "Test Page" also results in an image that is far smaller than that specified for the label size.

Suggestions, please?

I think I figured it out.

Printers - localhost -> Right click on the Dymo printer -> Properties -> Printer Options -> Media Size -> select whichever option seems best.

Once I changed up the media size, it now prints "normally," although it sounds very different when it prints so I'm not sure precisely what's going on.