Thanks for providing us with the tutorial you’re using.
So, the easiest way to test this is to create a sample project, which I have done. I have a persistent level and 2 streaming levels which I am using. In this blueprint, it also checks for whether or not the level is visible and if not, then it won’t unload a streamed level.
While switching in between the levels and the UI, I did not experience any movement with the player character. As long as you keep your character in the persistent level, your player character shouldn’t be moving out of alignment on the screen.
If you’re looking for a more simpler approach to loading screens, you may want to [review this tutorial][2] as well.
I hope this information helps you fix what’s going on in your project.