2017 Beta 300rr Throttle hang

[dirtynenow]

I am hoping someone else has had this issue and solved it.
The issue is that the throttle will hang and even accelerate. it is not the cable or carb, Beta replaced both for free, the OI is working correctly. Is there something else on a 2T that would cause this? I know on 4T it can pull hard enough to hold the slide up and that is why there are two throttle cables but on a 2T it should not be an issue. Any ideas welcome.
Thanks in advance

[aj_mariner]

When it hangs, do you still feel resistance when twisting the throttle?

[dirtynenow]

It does not feel like the slide is hanging, throttle snaps back like normal, the slide was replaced when the carb was replaced.

[aj_mariner]

It doesn’t sound like an air leak issue. Maybe gas tank vent or something not allowing enough fuel flow to the carb.