Product(WX746L.9) 20V MAKERX HOT GLUE GUN - TOOL ONLYGlued tiles in wet locations are not adhesive
(WX746L.9) 20V MAKERX HOT GLUE GUN - TOOL ONLY

Glued tiles in wet locations are not adhesive

Try this solution

Use a specialized adhesive suitable for wet locations

Possible cause:
Moisture spreads under the bonded area.