Product(WX045L) 20V POWER SHARE FULL-SIZE HOT GLUE GUNAdhesive surface only bonds on one side
(WX045L) 20V POWER SHARE FULL-SIZE HOT GLUE GUN

Adhesive surface only bonds on one side

Try this solution

Speed up the gluing process

Possible cause:
Part of the Adhesive already has cooled off before the work-pieces have been bonded.