Bug Canvas/Sub Canvas hierarchy issues. Possibly multiple bugs

Hello everyone.

After upgrading from version 2020.3.38 to version 2021.3.9, multiple oddities started showing up when interacting with the UI. As far as I know, the occurences below didn't happen on version 2020.3.38.

1. Button on an active sub canvas will still register input even with the root canvas not rendering(Turned off);
2. By disabling the root canvas, all the sub canvases turn off normally. By reenabling the root canvas, all the sub canvases show up normally. BUT if I toggle off and on any sub canvas, the root canvas stops influencing the toggled sub canvas. Though, if I toggle the GameObject of this sub canvas, it will behave normally again;
3. By ticking the Override Sorting box of any of the sub canvases, it will stop the root canvas from exerting any influence on the sub canvases with the Override Sorting turned on(Turning on and off the rendering of the root canvas won't turn on/off the sub canvases);

I know this may look strange, but this behaviour didn't happen in the previous version. Not sure if I am applying this the wrong way or if it really is an issue.

Issue 1

Issue 2

Issue 3