Hi @Anonymous,
Could you please share more details about the Ask in PowerApps dynamic content filled within Filter Query field of the "Get rows" action?
Could you please show more details about the parameters of TestLates.Run() function within your PowerApps app?
How many records does the "Get rows" action return?
Further, do you pass the Row id data from PowerApps app to the Row id field of the "Update row" action of your flow?
I think there is something wrong with your "Update row" action, if you fill the data from your PowerApps app within Row id field of the "Update row" action, the flow would only update the only record whose Row id is equal to the data you passed from your PowerApps app.
I have made a test on my side and don't have the issue that you mentioned. My SQL table's data structure as below:
Please take a try with the following workaround:
Within "Get rows" action, Filter Query field set to Ask in PowerApps dynamic content of the PowerApps trigger. Within "Update row" action, Row id field set to id dynamic content of the "Get rows" action.
The flow works successfully as below:

My PowerApps app's configuration as below:

The OnSelect property of the Button control set to following formula:
'20180412_case12'.Run("UserID eq '"&Dropdown1.Selected.Value&"'")
Best regards,
Kris