Printer should I consider?

[Hans Manhave]

I have four Canon MF455dw installed.  Standard as they come.  Laser, only using Canon brand toner (never clone refills).

Recently we found that there is a problem with the toner adhering to the check stock.  It can be easily rubbed of or flake of.

I blame the check stock because if I print 200 pages of plain paper, there is no problem.  However, there was no problem over the months of using the first 350 checks.  Of course, we don't have those checks anymore to inspect them if they are the same paper etc.  Our other two accounts with check stock from the same supplier appear to feel differently.  We print less than 10 checks per month of those and so cannot really tell anything from that.  Current provider states that there is no problem with their check stock.

Would one use an inkjet instead?  The above Canons don't appear to have serviceable fusers.

Order new stock from a different supplier?

Suggestions, please?