Below is a picture with the window not in maximize mode:

But when I maximize it it does this:
There is a black bar. This only happened just recently, and yes i have tried restarting my chromebook and mit app inventor
Below is a picture with the window not in maximize mode:

But when I maximize it it does this:
Does this only happen when you have the Companion app open? In a window/minimised ?
Does this happens on other web sites?
A black bar in the Chrome browser on a Chromebook [can be fixed by toggling full-screen mode with the F11 key](Google Search text**)
It's only on the companion app
That's on a chrome browser, not mit app inventor companion
Yes, my project is a web browser, and it happens even before it loads in (like the companion home screen)
Ran some tests on my Chromebook with companion app running, not seeing any issues, no black bar, working just as expected.
Yeah, same with my friend, he says it's not happening to him