I have the same problem, but only on 1 of my maps 3369-4671-4228
I went from 3 hitch rates to 60 with the December 1 update, and since then there’s been no improvement.
And yet construction mode is deactivated, in other games I have construction mode activated with as many vending machines and normal hitch rates, so the problem seems to be elsewhere.
Update 25/12: I deleted all vending machine and the hitch rate is back to normal. I just do not understand why in some games vending machine does not affect hitch rate, and others it does.