The issue I see is this - if I produce a flipbook with a fluid surface (mesh geo) and there is perhaps some other interactive object in the scene, there is a certain resolution you will hit in that mesh geo where other elements will drop frames. what makes it super weird is the flip fluid wont drop frames, its fine. but the other geo interacting with the fluid will either hold frames or drop frames completely, and its the lighter of the geo to be flipped. it hapens with both packed and unpacked objects
I've seen this with the flipbook tool and the opengl rop. what makes it hard to debug is it only happens in scenes when the resolution is being cranked up, so its hard to provide an example since there is always sensitive production data in there so I can't really provide a hip file for it, but I have seen it over quite a few shows, on different workstations, different studios since Houdini 15 or 16. I can't recall seeing it before then.
I should also note that the issue can occur without maxing out the video ram either.