Hi Spinba11 - welcome to the forum!
What I understand you are saying is that you can move the pit entry flipper by hand - that suggests you have the pit lane the correct way round.
You also say if you manually move it to ‘enter pit lane’ then as the car approaches, the flipper moves back to ‘straight on’. This is the default behaviour of a lane changer when a digital car goes over the sensor without the lane change button being pressed. This suggests the sensor in the pit entry is picking up a signal from the car and the solenoid ‘motor’ in the pit entry is working and closing the flipper. What isn’t happening is the pit lane receiving a ‘change lane‘ signal.
Could you repeat this keeping the lane change button (the top one) held down for the full lap - lap after lap. The car should change lanes on every lane changer and enter the pit lane each lap. Please do this with all three cars that came with the set and all three controllers. Let us know what happens and if any cars and/or controllers behave differently. That will help diagnose the problem.
Something I didn’t always get the hang of early in my digital experience was pressing the lane change button a couple of feet before the lane change sensor - I’d press too late and the car wouldn’t change. That also makes it important not to have lane changers, pit entries and powerbase too close together- I’d say three or four straights (or curves) between each.
I hope that helps.