Adjustment layers with motion effects over mixed resolution footage/cropped timelines are broken

This has been going on for several months now. I have a transitions pack which uses a mix of adjustment layers to create special transitions (zooms, wipes, camera shakes, spins, etc.) using a variety of motion/tiling/mirror effects.

These used to all work perfectly fine when working with footage of different resolutions (ex. 1080p and 4K), or when exporting cropped videos (ex. a 16:9 sequence cropped into 4:3 for instagram), but at some point last year an update broke them. Now those effects render as weird kaleidoscope-like clips. Everything plays back correctly in the timeline, and previews also render without any issues. The problem only happens on export, and having "use previews" toggled makes no difference.

Weirder still is that the effects work properly when exporting directly from Premiere, but not if you send to Media Encoder, but even then, ONLY when exporting at the timeline's native resolution. If you try to export a cropped timeline they won't work either way.

My workaround has been to render clips into the timeline's resolution, import and replace them on the timeline. I've tried nesting clips instead but it doesn't work. Or for a cropped export, exporting the entire timeline at full resolution then importing the full video and exporting a cropped version. Very annoying and time consuming work arounds for something that used to just work without any issues.

Attached a couple screenshots, one showing the expected effect in the timeline with a simulated camera shake, and one showing the exported frame tiled like a kaleidoscope.