It’s sometimes easier just to replace the device, but if you really need to fix it you can buy the heatshrink tubing with glue inside (get a size big enough to fit over the connector, like 1" dia) and just kinda squeeze it together while it’s burn-your-hand-hot. It’s crude but works.

Alternately get a hot glue gun, put a dab in that area and quickly (while it’s molten) wrap the area with some type of material like electrical tape carefully.