I know sometimes the launcher can show an advertisement that will block the normal screen. Do you see an X anywhere within the main screen (not the top right one that exits the launcher)?
That is good. I know that others have reported having the advertisement show up over the last couple of days. I use the beta launcher myself and haven’t seen it.
Glad to hear that the beta launcher is working around the issue! If you wanted to switch back and the advert isn’t showing up with the close (x) option, it’s usually caused by firewall or security applications blocking the advert. Troubleshooting the security applications and Windows firewall should help alleviate this problem.