TurboPrint & PrintFab

Unsure if this is the right forum section but here goes:
PrintFab 2.95, Canon IP6700, macOS Big Sur
Have been using the black ink frequently and yet ink level utility always show 100%. Prior to Big Sur the levels would drop with use but now am a smidge worried the real level is not getting read correctly.

Cheers.

Hello,

please open the "PrintFab Toolbox" app, click on your printer, then on "Open toolbox for selected printer" and then "Show ink status". If the ink levels are shown here, communication to the printer works. Then please compare if the ink levels are the same as reported in the print dialog or in macOS system configuration -> "print & scan".

Apologies for tardy reply.
So checking through PF's Toolbox shows me all tanks at 100%
However, going through Big sur's Print/Scan in System Prefs gives me "Info not available"

Again today, I printed 5 pages of text at 300 DPI and no change in the black ink level.