Why do saved credentials get lost when starting a service as a different user?

Question

Windows Server

I noticed that approximately after the May update of servers from 2008 R2 Standard to 2012 R2 Standard, mysticism began to occur sporadically.
A service started from another user (not from the system) runs, starts and stops successfully, it is worth restarting the server to install updates, and after turning on the service may no longer start. It will write that incorrect credentials have been entered, although no one has changed them, it is quite difficult to catch this, it has only happened 4 times. Colleagues simply do not believe that this can be, and it is difficult to google it. Who faced or in what direction to drip? According to the symptoms, it seems that the password storage is being cleared, but why is unknown.

Answer 1

Good afternoon!
Upgrade the build of the server OS .... yes, you know a lot about perversions (just kidding).
And if in essence, then they tried to recreate the service or change the user to the system one and then return it to the correct one again.