No longer recognize the sim card

my lem T watch no longer see my sim cards
to tell the truth i serve in nautical sport
I protect the sim card slot for more waterproofness, it rarely goes into water
there was no water under the location
apart from that the watch works normally
is the back cover easy to remove to see if there is a problem
thank you

Sim card or sims CARDS ? . If its just one you could try cleaning it with a small amount of alcohol . If its more one than you can try a full reset

unfortunately i tried two sim cards from different operators
i put a contact cleaner but no alcohol
I think I have more than open to see the damage

following the breakdown I opened the watch there was occidation on 2 pins I clean with perfume I have no alcohol, I think that the water these infiltrated by the mambranne of the speaker (can be cut)
the network is working again