F1 F2 F3 F4 Better ((better)) | Cid Font

If you tell me which software you’re seeing F1/F2/F3/F4 in (Acrobat, Ghostscript, printer, etc.), I can give a tailored fix.

CIDFont+F1 issue - Adobe Community

Understanding CIDFont F1, F2, F3, and F4: Are They "Better"? cid font f1 f2 f3 f4 better