Here is what Dymo has to say about this issue:https://global.dymo.com/enUS/RNW/RNW.html?pg=std_adp.php&p_faqid=68
Here is the text in case the link drops:
Why can't I cut
the tape after printing a label?
Every time a label is cut
residue from the label's adhesive remains on the cutter blade. This is
a normal occurrence when the LabelMaker is used frequently. It is
important to regularly clean the cutter blade in the cassette
compartment with either the special brush delivered together with the
LabelMaker (located in tape compartment door) or a cotton tip swab and
a soft solvent (e.g. alcohol).
If the solution above does not
resolve the problem, check for tape path obstructions. If the problem
persists, please contact DYMO Technical Support to obtain a Return
Material Authorization (RMA) number. To obtain an RMA number, scroll to
the top of this page and click on the Ask a Question
tab. Make sure to include your full name, address, shipping, and contact information.
-Hope this helps