Weird problem:
2018 TRD ORP, no JBL (any other options that could affect electronics?)
On Saturday (5 days ago) my fob worked great to lock/unlock my doors. Sunday (4 days ago) it stopped. I thought maybe the battery had died in the fob, so when I got back home I started to disassemble it to change it out, just to find that I didn't have the right one in my tool box. Later that night, I grabbed my second key to use and found when I attempted to lock the doors that it wouldn't work, either. Could it be both batteries were dead?
Next day, I bought new lithium batteries. Changed out the second fob I had with me (first one is still on the tool box at home disassembled) but nothing, no beeping or locking. When I got home, I changed the battery in the first one, and still nothing, no response.
Started trying to search online, forums. I am 99% confident there is nothing wrong with the actuators, since I'm not getting any responses with the fobs, but if I push the lock/unlock button on the door everything works correctly.
Found some programming procedures, but then found they were older years, and 2018 (according to NorthCoastKeyless.com) can't be put into programming mode, you need a locksmith (I'm assuming with a scantool.)
Last night, I went over to a buddy with a newer scantool to check for any body/security codes. Out of habit, I hit my lock button on my fob (the first fob) and heard a beep! WTH!! So, I happened to have the second fob in my coat pocket, tried it, still nothing. But the first one now works! We did check for codes, and found a U1002 (lost communication with gateway module) and U1114 (lost communication with main switch module), both under 'Main Body' and both in history.
Went back online to do some searching for those two codes, but I'm not coming up with anything substantial. Our hunch is maybe I'm getting a battery that's starting to go out, so power fluctuation caused the loss of communication? But that's just a WAG.

Since I can't find anything when I search, I figure this won't be a hot topic on here, but if anyone has any insight to this problem, these codes, or where the hell the 'gateway module' or 'main switch module' are located, I'd love some help with this.

Ive had the same issue and every time I replace the battery and it works as normal.

I bought some amazon brand batteries and they only last a month or so. switched to some energizer or duracell and havent had an issue.

The fobs seem to sensitive to lower voltage and dont transmit as far.

That does make sense. I used Energizer Lithium. I haven't actually checked the voltage on them, but I might double check the second fob that isn't working.

yeah, this sounds very much like a battery that's on its last bit of juice

Really agree with your point. Power devices need to be tested to make sure they work. Batteries have cycles and need to be replaced periodically so be aware.

Just a SWAG as I ran into this way back.

My wife decided to bring her remote along to dinner. My remote would not work until she was well away from the car.

No issues since, keep the second remote locked in a metal safe now.
Might have read something about them getting confused with two fobs nearby.

I had a similar problem that caused the doors to immediately unlock themselves after pressing the lock button on the fob. I had this zippo plugged into the back 12V socket with a USB plug to keep it charged. It was inadvertently feeding back some voltage into the truck 12v and tripping up the lock.