Thanks for posting this, this definitely sounds like odd behavior.
Are you setting a background image to the slide itself? If so this may be the issue. Components in Webflow have some settings that, if changed, will cause them to not function correctly. In the case of the slider if the slides’ display / position settings are changed they may not work correctly.
I typically recommend adding a div block, setting it to 100% width and height, then setting a background image there instead. Can you please try using this structure to see if it resolves the issue?
If this doesn’t help, can you please share your Read-Only link so I can take a closer look? Can you also let me know what page and section your slider is on?