Hi plotly team!

I'm trying to implement a plotly viewer for .nii files, analagously to the tutorial that already exists for mri volume slices (https://plot.ly/python/visualizing-mri-volume-slices/), but can't seem to get the slider bar to work. I've noticed that the output at the end of the tutorial doesn't work either and was wondering if something has been changed in the animation/slider code that caused this. My adjusted code at least plays the very first time I plot (I'm running it all offline but it shouldn't make a difference), but the slider and subsequent play clicks have no effect. Interestingly when I click on play and then move the slider, the images animate once through the "play animation", but only when I'm actively moving the slider and just one frame at a time, without any correlation to slider position.

I've also found this implementation of animating surface images (https://plot.ly/~empet/14887/animating-slice-in-volumetric-data/#/) that has the same problem. The initial autoplay works but all subsequent slider movements don't have any effect.

Any idea what might be causing this?

Thanks for your time!