I have created a PowerApp connecting to my SharePoint list. When I select an item in the list and click on Edit, I see form opening as expected. The form has a Dropdown list for Region. I click the list open, and without selecting any item or without clicking outside the Dropdown, I close the item.
Next time I click on another item in the list and click on Edit, I see that earlier dropdown (which I opened for earlier item) is still open and has values of earlier item.
Do you use the Custom form created in your PowerApps app to edit the list item within your SharePoint list?
I have made a test on my side and don't have the issue that you mentioned. I agree with @ChrisR's thought almost, you could consider take a try to set the OnEdit property of SharePointIntegration control to following formula:
In addition, please check if the OnSelect property of the Combo box control within your SharePointForm1 is set to false. Please take a try to set the OnSelect property of the Combox box control within yout SharePointForm1 to false.
You could also take a try to re-customize a form using PowerApps app for your SharePoint list, then check if the issue is solved.
Community Support Team _ Kris Dai If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.