NAV 2017 - issue printing to Zebra Printer due to margins

I have a client that is having inconsistent issues with margins on an RDLC label report printing incorrectly. In 2017, I already know of an issue with the printer ignoring orientation settings (not the same bug as the one reported in the cumulative update, there are no printer/report selections), however we are getting around that by sending page parameters that would be intentionally wrong if we were printing to paper. This works for the most part for this client and others, however this particular client will sometimes have the margins a half centimeter off on top or bottom of the label, which causes the report to spill to another label. All margins for all sides are 0.2 cm in the RDLC report properties, however it is printing with easily a 0.5 - 0.6 cm bottom margin.

We have run the Zebra calibration routine, and the client has an older non-Navision label printing program that prints without any issues with the margins. I also have all fields on this label set to CanGrow = False and have triple checked that all text boxes are within the printable area (with a little extra to spare).

Has anybody else run into this? The fact that it is intermittent originally made me suspect that recalibration was necessary, but since the other program can print without issue, clearly it isn't the calibration. I cannot think of anything else that might cause the margins to go awry.