Whever I connect to my 2012 Mac Mini server (1TB SSD 16 GB RAM) I can't see the contents of any window.  They just look like white boxes.  also, the area where the desktop icons are is also just a giant white box.  Any idea what is causing this?  I want to love this remote solution and it has been pretty flawless everywhere else but I need to connect to this and 5 similar machines with some regularity.

Thanks for any insight you can provide

SK