Power Apps Combobox not showing updated values

Question

Hello. We are developing a canvas app. In that we have a combobox that is associated with "staff" list. We are fetching all staff name here. The issue we are facing is, after publishing of our app, client has added few more staff person name in the list but it is not loading in the Combobox. But if we search them, they appear. The list has 422 records. When we try to replicate scenario in our dev tenant, it is not having that issue. We have tried with increasing data row limit to 2000. Also, we have refreshed the data source and tried to access app in incognito mode to verify its not cache issue. But nothing works. Below is screenshot for list, combobox normal result and combobox search result.

 

 

 

 

 

 

 

Can someone guide us if there is anything we are missing?