I have a 2014 4Runner that I have replaced 3 of the door lock actuators on. For the last 6 months I've been having random lock issues. It's never that all or none of the locks work but individually they'll quit working for a day or two and then come back to life. Yesterday it was both front doors. Now it's just the driver door. Last week it was the rear passenger door. It's been this scenario off and on over and over again. Sometimes hitting the lock/unlock button a couple times on the door will bring the broken lock back to life and sometimes it won't. I feel like there has to be some sort of electrical issue for it not to be one door constantly not working. I've read multiple threads on here but it seems like most issues are either one door failing with a new actuator being the solution or all locks failing at the same time due to a fuse or a body control module issue.

Has anyone else experienced this? It's about to drive me crazy. I'm so tired of trying to figure out which door isn't locking when I hit the lock button on the remote and it doesn't beep.

There are a few threads on this issue as it's not a new one. In one of them is a source for actuator motors much cheaper than OEM and instructions on how to change them out. There are also other threads on how to remove the door panels to access the actuators. Look in the stickys and or search function for the threads that best help your situation.

I've already replaced 3 actuators myself. This is not an actuator issue. There has got to be something else causing them to randomly stop working and then come back to life again. Over and over and over again.

My 2011 4Runner (purchased new) started doing this exact same thing in 2016 with an odometer read of approx 85K.
The dealer service department fiddled around with the key fob and internal door switches and suggested replacing 2 door actuators.
This is a very expensive repair so I declined.
A case was created with Toyota Customer Care which was eventually dismissed
due to the number of complaints not hitting the recall level but acknowledged as being an issue.
Unfortunately I have learned to live with the inconvenience.

Wife is having the same problem on her highlander.

Works sometimes and sometimes it doesn't. Tried both remotes and new batteries. I've been trying to find online the location of the receiver or controller for the remote but no luck yet.