The issue you are facing with this widget, you are depending on the DOM at time of the activation of the widget. This might cause several issues, as the client can render any part of the HTML DOM at will. This is a property of React.
Test what happen if your tool tip is attached to a part of the page that is hidden and shown again with conditional visibility.
There is no real solution to this. You could have a look at “observers” but they might kill you client performance.
About your challenge what “modal” are you referring? Is this a modal page or a dialog?
You can PM me via community Slack is you need some help
IOP the best tooltip option – https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/title
something wierd that sometimes happens with top level widgets, is that if MX is started in a certain layout, if you than switch layouts, it loses context.
you could create a “top level layout” add your widget to that.
Than master layout both the atlas ones to your top level layout.
This might not do anything, but its worth a try :D