Flickering LED’s

I have a 22 SR5 TRD off road with the 8” screen. It’s been near flawless for almost 2 years but an issue arose I’m hoping one of you guys might be able to help with.
It’s been raining here (Manitoba) pretty good the last while. My issue started with the side marker lamp on the drivers side in the tail light flickering after turning off the truck for the while the lights stay on but operated as normal with truck running. That changed to what looks to be a burnt out LED that only has one of the two on at all times but looks dim. I noticed moisture in the light so I took it off and dried it out but nothing changed.
Next up a few days later I noticed my backup lights flickering after turning it off but stable while running. That changed into a flicker while running also.
Lastly, on my drive home last night in pretty good rain, the display changed from CarPlay to the backup camera and backup lights were on. It started as intermittent but changed to being on consistently.
If the truck sits overnight and dries out, it seems fine but the issues reappear as soon as I hit the wet stuff again.
I’ve called my local Toyota dealer but they are booked up for a week so I’m reaching out to you great people instead. Does anybody have any idea what could be the cause (I know it’s moisture but I don’t know where to look!)

 

Check and see if your alternator and battery are providing the voltage. Flickering LEDs is one sign of incorrect voltage hitting them. Went thru this when I upgraded my daughters 09 Venza. All I got for you