nomadio react phantom sensors?

so i just recently purchased a nomadio react on the bay. i run it a couple time no problem. i then install a temp sensor on the motor that works fine. today i take it out in slightly wet conditions and it says temp 3 is 250 degrees F and temp 4 is 400+ degrees. i only have 1 temp sensor on channel 1 and it is accurate (checked with temp gun) was it the moisture or what, it (reciever) never was soaked or splashed.
any ideas or similar experience