automation is bugged and resets

For some reason several water depth sensors keep resetting to their lowest possible value. It happens on every reload, but more annoyingly after a few minutes of gameplay. it will just dump it's height measurement. I first noticed a cycle ago when i had no water left because the sensor which had been there for nearly 25 cycles just has a value of always on while checking the depth of my reservoir, therefore dumping all my water. I'd done nothing different about it for about 25 cycles as it just worked perfectly and then started being weird all of a sudden. It now happens to other automation things too, seemingly the oldest ones i've placed first. I'm on cycle 33 (barely survived going 20 days without water at all, i've got 12 beavers now) and been replacing all my automation with reliable good ol fashioned dams and sluices XD
I'm assuming the save file has exceeded memory storage or save size or something? It's not my hardware, i've got loads of ram, rom and everything else.