You stand still for up to five seconds, even though there are no vehicles nearby, until clearance is given. Gaps between vehicles are ignored, even though 10 vehicles could fit between them.
Ideas
I was having the same issue until now, but it got fixed for me. Here is how I "might" have fixed it:
Go to Settings > Assists > Pit Assist Release (from off to on) > close the game > reopen > Settings > Assists > Pit Assist Release (from on to off)
FYI: A new season began, and my pit box was sent from front to back in the pit lane.
I hope this helps because it worked out for me. 👍
For me it was on, I turned it off after going back to a mid session save right before I pit, turned it back on after the pit and have had no issue in 4 races.
But my pit box is still where it was based on the race I am at.