
Hi @NR-07101917-0,
I have not run into this precise behavior before, so let me frame a few checks that usually surface the root cause.
The signature you describe, worked for months, no changes on your side, now returns null with no error and a successful run, points almost always to the list crossing the 5000-item view threshold. Past that limit, Get Items stops returning matches on non-indexed columns, and it does so silently. The run reports success. That is by design, not a bug, which is why recreating the action seems to help. The new action starts with different pagination and top-count defaults, so it masks the real issue until it resurfaces.
A few things worth validating before you rebuild everything:
If the list is under 5000, the threshold theory does not hold, and the likely culprit is a stale schema cache from a renamed or retyped column, where the Filter Query references an internal name that no longer resolves. That returns null rather than erroring.
There is also a search indexing angle worth ruling out. Newly created items are indexed on a delay, and if anything is caught in a reindex or the column was recently added, the new rows will not surface in filtered results until indexing completes. Worth confirming the timing of when the new items were added versus when the flow ran.
Start with the item count. That single check tells you which path you are on and saves you rebuilding actions you do not need to touch.
References