Vintage Anamorphic + IBIS = Jello? Need help diagnosing warping

Hey everyone,

I'm encountering a frustrating issue on a current project and hoping for some community wisdom. I'm shooting a short film, and for a specific look, I’m pairing a vintage LOMO anamorphic lens with an ALEXA Mini. The camera has IBIS, which I normally love for Steadicam work, but I'm getting a noticeable 'jello effect' or warping, especially on horizontal lines when there’s even slight camera movement. It's not constant, which is making it hard to pin down.

I've tried reducing my walking speed and being extra smooth, and even disabled IBIS for some takes just to compare, but it's still there sometimes. It feels like the sensor stabilization is fighting the anamorphic's characteristics.

What are the first steps you’d take to diagnose and then hopefully fix this type of 'jello' or warping when using a vintage anamorphic with an IBIS-enabled camera?