Screen mirroring broken under iOS 14?

I’ve been using an app called SeewoLink to mirror my iPad and iPhone screen to a Seewo smart board. I work in China and it’s what my school uses in each of its classrooms .

Since the latest iOS update (14.0), I can’t get either my iPhone or iPad to mirror its screen to the Seewo smart board. The device simply doesn’t appear when I select Screen Mirroring from the control center.

Both devices are connected to the same network, and I can use the app to control the smart board screen normally, but I cannot mirror my iPhone or iPad screen. Is there some sort of security permission I’m not finding that will let this happen?

Thanks in advance for whatever help you can give me.