Hello,
I own a Beelink GT1 Ultimate.
A few days before I noticed that I can't connect my phone (XIAOMI REDMI NOTE 4X) to the android box thourgh Miracast.
I tried various apps on the phone but none worked with the Beelink's MiraCast.
I checked my phone with my Smart TV and it worked perfecly with 3 different apps and the youtube.
I assume that this is a problem of my Beelink.