Star Wheel problem, people are not stepping into it and kept waiting in the queue

[TAKAKIKAO]

I just built a Star Wheel at my park and found out that people are stuck at the queue and not getting on broad...Anyone knows what's the reason?

[Fogtreadder]

It may be caused by the minimum and maximum wait times in the ride's settings. If you have made adjustments to them then there might not be enough time for people to actually get on the ride before it starts again.
However, I have seen this happen with other rides when I have not made changes, so I think there is also a bug that causes this sometimes. Try changing the ride load, Any Load, Half-Load, Full-Load. You can do that without closing the ride. The people in line will shuffle about and then you can set the load back to where you want it. I have used this to clear peeps who got stuck in an awkward place on coaster platforms too.
If that still is not helping, then close the ride, get all the people off the platform and the entrance cue, then re-open.
One other possibility may be the rides placement. When playing the campaign I sometimes had ride platforms conforming to the shape of the terrain. When this happened I saw your issue come up more often. Sometimes I could not even connect paths to the entrance and exit. Flattening the terrain before placing the ride, or just elevating the ride a bit to make its platform level, helped with that.