power-fx-review

Replace non-delegable functions with delegable equivalents: swap Search for StartsWith with Filter, use = comparisons instead of the in operator on SharePoint, and avoid aggregations over large sources. Set the Data row limit to 1 while testing so any remaining non-delegable part collapses the result visibly.

A non-delegable query causes Power Apps to pull only the first 500 records (2,000 maximum) and run the operation locally, silently dropping the rest. Check for Search, CountRows, IsBlank predicates, or aggregations in the Items formula and rewrite them with delegable operators.

A LookUp inside a gallery fires one network call per rendered row, causing N+1 performance. Pre-join the data once in the screen's OnVisible using ClearCollect with AddColumns, then read the joined field locally via ThisItem in each row.

IsBlank tests a value for blank or empty string, while IsEmpty tests a table for zero records. Calling IsBlank on a collection always returns false even when it has no rows, so use IsEmpty to check whether a collection or table is empty.

Use SubmitForm when the screen has an Edit form, since raw Patch bypasses the form's validation, Error handling, and Unsaved tracking. Reserve Patch for scenarios without a form, and prefer a single bulk Patch over Patch inside ForAll for multi-record writes.