Sidecar connection issues and app duplication with Command + Tab on MacBook and iPad

Hey guys I just recently got a Macbook Air M1 (2020) and I found out by accident that I can use my iPad Air (4th Generation-2020 I think?) as a secondary screen! I've got two problems with it currently thought:

1. A few times I've moved away from my desk taking my iPad with me and forgetting to hit disconnect. After getting back to my desk, it says "Unable to connect to - This device timed out," even though I have them right next to each other and everything turned on/enabled. Even connecting them with a usb-c - usb-c cable it still gives the same error. The only fix is turning it off and on again, which is a pain as iPads don't have a reset button and resetting my Macbook always makes me have to rearrange my windows.
2. When I am able to use it, when I command + tab to an app where I have a window on both desktops (using the iPad as an extension), it brings up the app on both the MacBook and iPad. This is really annoying as I usually have a calendar, timer or notes opened up on my iPad screen. I don't want to pin those apps (if there is even a way to) to the screen as I switch between them often.

I'm on MacOS Sequoia 15.6 and iPad OS 18.6.2

[Re-Titled by Moderator]

Original Title: Can't Reconnect Screen Mirror to iPad After Moving Away and With Switching to Another App with Command + Tab Brings Up App On Both Macbook and iPad When Using Sidecar