My SSRS report has multiple Tablix elements. Their visibility is conditional to the content of the datasets they use. It works as intended when first displayed. When the dataset is empty, the Tablix is hidden. It's done by using "Show or hide based on an expression" option on the properties of the Tablix. One of the Tablix elements is setup with a Group where the Detail is only visible when the a group field is toggled, which works as a "collapse" or "drill down. Example As soon as the the group is toggled, the screen refreshes (not the report) and all previously hidden Tablix elements incorrectly appear (empty).
I have tried in different browsers (chrome, edge, explorer) and they all do the same.
=IsNothing(Fields!ID.Value), I get the behavior you are experiencing where the empty tablix is initially hidden but then appears when I interact with the other tablix. If I instead do=Count(Fields!ID.Value) < 1, I get the intended/correct behavior. I'd try refactoring that expression if possible and see if that works.