On the MBTA CTC-3 cab car, the in-cab ACSES speed limit display and the speedometer updates only when you go to exterior camera and then back to cab view. If you stay in cab view when the speed limit changes you can hear the beep from the safety system but the display will stay the same, making it impossible to play with no HUD without constantly changing between external and cab view. This has occured to me in 15:03 service from Providence to Boston. I'm on PS5 and the game is TSW4.
Indeed, this is an issue on Steam as well. On Steam, pressing 1 activates the internal camera, pressing 2 activates the external boom camera (the TSC camera) and pressing 3 activates the TSW external camera. Pressing 8 activates the free detached camera. However, TSW4 silently introduced a new feature where pressing 1 will reset the internal camera's orientation if you are already in the internal camera. This has the effect of updating the ACSES display. I don't know how to change cameras on a Playstation, but if the button the enter the internal camera works like it does in Steam, you can press that whenever the beep happens with no need to go to the outside camera. For speed, I use the analogue display in the cab car.
I plugged in a keyboard and pressing 1 seems to update it as well. I still hope that it would be fixed since it's pretty annoying to constantly press 1 and then look back up again.