Driver's door does not lock with remote

Hoping some of you can help with a minor issue I'm having with my '14 Tundra...
When I click the remote door lock on my key fob, all doors except the driver's door lock. So I have to lock it manually with the key. This does not happen every time, roughly 60% of the time. I have put a fresh battery into the fob, but no joy. Just today, the driver's side rear door started acting the same way. I tried using the second key fob that came with the truck, but same result. I can't seem to find a pattern of when or why this is happening. I suspect it is something electrical, although I don't have enough knowledge of the electrical system to confirm this. I do have an aftermarket remote starter that was installed when I bought the truck, so I do use a different key fob, but when I try the originals (with fresh batteries) the same thing happens. So hopefully, one of you has experienced this and has a solution. I'm certainly no mechanic or electrician, but I'm optimistic that with some sound advice, I can correct this issue myself. Let me know if you need any other information to help me fix this issue.
Thanks in advance for all your help!

TC

 

Probably your actuator. Toyota vehicles have a history of their door lock actuators going out. Pretty simply fix. You can look up YouTube videos on how to replace them. Word of advice, you don't have to buy OEM. Anything from ebay so long as its for your truck will do. I personally spent 20 bucks in total to replace the actuator on my corolla

 

Yep definitely sounds like the actuator is on the way out.

 

Its the actuator, you can replace the motor in the actuator for about 5 bucks. I have a thread about why they go bad. The motor doesn't spin enough to throw the excess brush material off of the commutator, so it gets material built up and it causes a poor connection. You can clean the brushes ams comm and it will work fine. I'll post the link shortly

https://www.tundras.com/threads/door-lock-actuator-motor-failure-w-pics.61628/

 

Thank you, gentlemen, for the replies and the link. I appreciate your help. I'll clean everything well and see if I can get some more life out of the existing motors. Thanks again!