The old method no longer works because tick event stops running when visibility is set to hidden or collapse.
Widget Component don’t work either because it is not “touchable” for mobile
For mobile, what other ways can I use for a UMG (button or image) to follow an actor?
Why would you need the tick in an invisible widget? Wouldn’t it be easier to use actor’s tick (the one the widget is supposed to follow) and set position of the widget (if that’s for tracking purposes). Or even easier, attach the widget component to the actor - is this an option in your project’s case?
I have little to no experience with mobile but have you tried tracing against the component, the same method that is used in non-mobile projects?