There is a limitation with List rows present in a table action which only return 256 rows only.

We can retrieve more rows by setting a higher value for the pagination settings.

1. Go to “List rows present in table” action
2. Select the options elipses (“…”)
3. Select ‘Settings’
4. Enable Pagination
5. Set an appropriate Threshold value
6. Click on “Done” button. The ‘List rows…’ action will now return all the rows.

Please see the below screenshots for more details: