Normally, if for any reason the printer is not able to detect the gaps, the printer will feed some labels and you will read the following error message at display: "OUT OF PAPER".
You are saying that the printer is reporting "Check Paper Path ..." , so, seems a different problem.

1st step:
Please, let us know the exact error message because there are 4 types of "Check Paper Path and Restart (x)" ... we need the number at the end as it could mean:
- a paper jam, or rest of labels at rear module.
- a paper jam or rest of labels at line feed roller.
- something is blocking the carriage.
- something is blocking the SVS.

2nd step:
Unmount the rear module and check if there is any rest of labels or something that could be blocking the paper path & normal way of work.
Check inside of the printer if something is blocking the paper path to the line feed roller.

3rd step:
Turn on the printer, load labels (better a size of 150x100mm or similar) and execute a Print Test label A a couple of times, in order to see if the printer is detecting the labels and is printing fine. The "Test print A" is a internal design on the printer, in this way, the effects of external software will is "out of the formula" and will make the troubleshooting more easy.

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