Storyline 3 fly-in animation jerky on LMS

Hi everyone,

I have a problem that I haven't seen specifically addressed in discussions.

I have a very basic file with text, images and simple animations. It plays fine for me in Preview and on SCORM Cloud - but when I publish to LMS, the animations jerk on specific slides (not necessarily every slide).

I learned in my research that masking animations are stuttery or broken in some browsers/LMS. However, I'm using Fly In on this one, and using Chrome.

I've checked my Slide Master (this build was handed off to me so I didn't create the master). It looks fine to me, but I've only been doing this for a while so may be missing something.

I also learned that sometimes this can be an LMS settings (bandwidth) issue. I reached out to the LMS support team. We had a video call and I shared my screen to show them A) the course in LMS and B) the course in SCORM Cloud. Their response is that they "don't really see much difference and it looks fine to them," which is just... well, I see a huge difference and it's not fine at all from a learner experience perspective, but now as well as being flummoxed, I also worry that I am insane :).

If it's an issue with my build, I would love to know so I can fix it and never do it again. I would be grateful for any help this community can give.

Attaching an abbreviated (just a few slides) published file, .story file., and a screen capture of what it looks like on LMS.

Thank you!