Well that was unexpected and unfortunate. I’m also no specialist of vue, vite or react 
I think we have identified that the problem comes from the part where you say
Does this affect only the GUI or do you see any other changes in the scene?
I think you should may be try two things around these lines:
Either use engine.getRenderWidth / *Height (instead of canvas) or add a resize event listener with the script that’s in this post. I would play all too much around hardwareScaling though.
I hope this helps… Meanwhile, have a great day 