Make sure to use Lumin software app, not the Teac software app for control. Lumin app is more stable and is compatible with the player.
I also haven’t had any trouble with my NT-505. Although I did have trouble initially updating to current firmware version. I was connecting to the USB (the larger one labeled USB) on the back rather than the micro USB (very small, unlabeled, near bottom), but once I figured that out it was good. Sorry can’t tell from your last post whether you have successfully updated to current version or not.
@audiojedi did you mean version 1.21 firmware, or did your really mean 1.22? Isn’t 1.21 the latest?
EDIT: Nevermind, I see that 1.22 came out now.
OP, sorry for my basic descriptions but you know the NT-505 doesn’t have wifi, correct? It is Ethernet only. No wifi. I think your references to wifi in your post refer to your wireless router, just wanting to make sure you got that which I’m sure you do.