Ran a service up the mountain tonight and saved the game midway through to go do non-game things. When I loaded back in, the alerter sound effect could continually be heard while in any exterior view, regardless of alerter status in the cab. The alerter in the cab worked as usual, and no emergency braking, etc. resulted. It seemed to just be a persistent sound effect. Note that this was all exterior views, even driver's POV ones like leaning out the window. It had been working normally prior to loading the save. I did check the other locomotives to see if the alerter was on in any of them; none had the alerters even turned on. Good luck!
It's the save game, for whatever reason it does some odd things with different routes and services even causing a red light bug and then there is when the save game works without issue. "flip a coin"
Yeah, seen some isolated weirdness after load before. But tis better to report than not report. Unless I picked the wrong place.