I'm really surprised this isn't a bigger issue, or is remote play just not that popular?
In the last few years maybe 5 questions regarding remote play came up and none of them where related to your problem. Usually just general setup questions to get it running.
I made a new thread today about this very thing. This always worked up until the last couple months. Exact same issue, only when Xim is connected. If i remove Xim it wakes up and logs in fine. Also, in front of console starting from rest mode works fine.
After reading another post saying you can connect Titan to it and it will work, I remembered that i had Titan connected up until a couple months ago so thats when it must have stopped working.
I'll see if i can delete my other thread