This is what is in the DESI manual

Quote
Chapter 9 - Troubleshooting
Printing Desis
“My printer feeds the DESI sheets through without printing anything”
or “My printer only prints the first few lines of the desi.”

This is caused by the “end-of-page” sensor in your printer. This sensor
“sees” the holes in some desi sheets, and assumes that it has reached the
end of the page. The printer will then stop printing and eject the page. A
test to verify that this sensor is causing the problem is to print a desi on a
plain sheet of paper. If your desis print normally on a plain sheet of paper
but not on a desi sheet, the sensor is causing the
problem.

Solution: Desi Telephone Labels, Inc. produces specially-designed
Post-it™ notes, called DESI Backers, that can be placed on the
back of the DESI page to cover up the holes that are triggering
the end-of-page sensor. See the front cover of this manual for
information on ordering DESI Backers.


https://labels.desi.com/product-exec/product_id/812/nm/DESI_Backer_Oversized_Post_it_Notes

Which sounds like you tried already.

There is no such thing as stupid questions.
Just stupid answers.