DYMO 450 Label Printer keeps stopping midprint and blue light starts blinking, please help.

As title says, my Dymo 450 label printer keeps stopping midprint – after a few seconds, enough to print just three or four labels – and then the blue light will start blinking.
I've done everything. Uninstalled and reinstalled drivers and printers, restarted my Mac (I'm on Sequoia 15.7.1) but nothing works. I've used this printer a LOT in the past, I've printed thousands of labels with it (and no, I'm not using DYMO labels but the cheaper ones I'm using are the same brand as always.
Yesterday I managed to print a few hundred labels without issues but today I'm seriously considering tossing this damn printer in the fire.
Please help. I need to print lots of labels as soon as possible.