Hello Nik, sorry about your problems. My name is Marco and I will do my best to help you.
You need to hold the ALT button, then by pressing TAB you can select the windows. What's new with Edge is that Edge's tabs are "included" in the ALT-TAB, so you have to press TAB several times to change windows.
To turn it off, it's where you said. You must select "No tabs".
If you mean these are the tabs in Edge directly, you can do an Edge repair as follows:
Make sure that your browser is closed and that you have administrative rights to your device. If multiple users are logged in your device, make sure Microsoft Edge is closed for all users.
Go to Start > Settings > Apps > Apps & features.
In the apps list, select Microsoft Edge and then select Modify. If the Modify command isn't available, it's likely that your organization installed Microsoft Edge and is managing it for you. For help, contact your system administrator.
When prompted Do you want to allow this app to make changes to your device?, select Yes.
Make sure you're connected to internet and select Repair. Your browser data and settings shouldn't be affected by repair.
source: https://support.microsoft.com/en-us/microsoft-e...