Sudden change in print quality

Hi, I'm looking for any advice/help with print quality from InDesign. I design fonts and proofing with high res prints is a staple. All of a sudden I cannot get InDesign or PDFs to print high res text anymore, the result is either pixelated, jagged or shows slight dot cut always in the outlines at 10pt. Printing from any other application at 1200dpi has crisp dark text, however what ever options I adjust in InDesign I can't match the quality.

For quick proofs I print directly from InDesign, via deselecting "Print as Bitmap", selecting Transparency Flattener > high resolution. As of today Transparency Flattener is greyed out. When I deselect "Print as Bitmap" it doesn’t stick or unlock the Transparency Flattener. If I change the menu and return, Bitmap is still selected, also evident by reading the summary. I've always used this method with perfect results, but as of a day or two ago it's not working anymore. I'm unable to select High Resolution. No settings were changed. I’ve tried exporting to PDF print / high quality print but the result is the same. I’ve tried from another laptop too. Any ideas? Thanks in advance. 

MacBook Pro M1 - Brother HL2370DW - Latest OS X and CC update