Hi @Anonymous ,
How many records existed in your 'Purpose of Data extraction' List? More than 2000 records?
The Delegation issue is not an error in PowerApps canvas app, it just means that you could not delegate the data process from your canvas app to your SP List itself, instead, you could only process the data locally in your app.
In default, you could process 500 records locally in your app, you could change the "Data row limit for Non-delegable queries" option to maximum value -- 2000, then you could process 2000 records locally in your app.
Please check the following article for more details about Delegation:
https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/delegation-overview
Please set the OnStart property of App to following:
Set(CurrentUser, User().FullName)
Set the Items property of the Data Table to following:
Filter(
'Purpose of Data extraction',
TrackingID in Filter('Request List', 'Created By'.DisplayName = CurrentUser).ID
)
then re-publish & re-load your canvas app, check if the issue is solved.
Based on the needs that you mentioned, I think the formula I provided above could achieve your needs.
Best regards,