as mentioned in the DALE series by @T-low
there is an issue with the Query block while excluding from the Query with dynamic parameter set to an ACF relationship field.
This issue happens on the backend while the display on the front end works.
Because of the new way of displaying the block (with the blue previews) when the Query is not resolved, this prevents from creating or editing the blocks included in the Query template, so each time you need to make a change you need to change the query to a fake working one and reset it to the one you need…
Plus, while setting it up, to have the block not working make oneself doubt about one’s ability to understand the quite complex Query…