Warp Stabilizer and Interpreted Frame Rate Footage

Hi Everybody!

So I am working on a fresh 4K transfer of some silent film footage. Although a new transfer, it was done at 24p and thus runs too fast, so I am interpreting the footage at 18fps. All is fine until I run Warp Stabilizer on the interpreted footage. The stabilized clip seems to be back at 24p (it definitely runs faster and both the head and tail include material beyond my edit points). I've tried, nesting, subclips, et, and the stabilized clip either: (1) runs fast as above; or (2) is at 18fps but no stabilization occurs.

As a test I created a new project at 24fps without interpreting the footage and everything works perfectly, so it's definitely something to do with the interpretation, but I can't figure out what or how to fix it. I am running Premiere Pro 2024 on Mac OX Ventura.

Thanks in advance!