Labels that come out off-centre, clipped at the edges, or with a blank label between each one almost always have the same cause, and it is not your printer's calibration - a printer that prints correctly from other label software will still do this. Your browser is fitting a label-sized page onto whatever paper size the printer driver has selected, and when the driver's printable area is even slightly smaller than the label, the overflow spills onto a second label. That second label is the blank one, and the same overflow is what pushes the artwork off-centre and clips it.
Print straight to the printer
The reliable fix is to take the browser out of it: install Dymo Connect or Zebra Browser Print and set Settings > Labels > Printer as described in Print straight to a Dymo or Zebra label printer. Stockroom then sends the printer an image the exact size of your label, so there is no paper size to mismatch and no page to spill.
Or set up the browser print dialog
If you would rather keep using the browser print dialog, set all three of these every time you print:
Paper size - pick the entry that matches your label, not Letter or A4. Dymo installs one per label type, for example "30332 1 in x 1 in".
Margins: None, under More settings.
Scale: 100%, not "Fit to page" or "Fit to printable area".
The print preview tells you whether you have it right. One label should be one page. If the preview says 2 pages for a single label, that second page is the blank label you are about to feed - change the paper size or the margins until it says 1.
Good to know
If the label is blurry or the barcode will not scan, that is a different problem - see Set your printer's resolution in Print straight to a Dymo or Zebra label printer.