Remote Desktop onto Ubuntu 16.04 Fails Only From Android Devices

I am running XRDP on an Nvidia Jetson TX2 running Ubuntu 16.04 LTS for an underwater microscope. I can remote in via an ethernet cable, or WiFi configured as a hotspot. Both of those connection paths work generally, and I can successfully open a remote desktop connection to that computer from other computers (Windows 10 and 11), iPhones, and iPads. However, so far no Android device can connect successfully. We've tried multiple phones, remote desktop clients, and others with no luck. So why are we bothering trying to use an Android? We have an Android device (1+ Nord N200) for fieldwork with a large screen and an underwater housing that will allow divers to operate the microscope through the remote desktop underwater. What works on every other device: - Microsoft Remote Desktop, either via ethernet or over the hotspot. Note that both can be used simultaneously for these other devices (i.e. one device over ethernet, one over WiFi). - No port needs to be specified, though xrdp appears to be listening on port 3389 - IP address assignment for the WiFi left at default of Automatic - xrdp login screen loads almost instantly On Android: - If no port is specified for the IP address, Microsoft Remote Desktop gets stuck on "Configuring Remote PC" - If a port is specified: Immediate failure due to protocol error (0x1104, 0x500d,etc.), stuck in the "Configuring" loop, or claims it cannot find the IP address (error 0x104), depending on which port is specified. - Able to ping the IP address, even if 0x104 code was returned. - Other remote desktop apps (VNCViewer, Remote Ripple) also fail to establish a connection, returning similar errors/entering similar waiting loops. - This is true for automatic or static IP assignment - This is true for multiple different Android devices My thoughts are that it's probably something simple and fundamental that I'm missing, perhaps some basic port difference between Androids and other systems, but none of the posts I've scoured through so far have helped figure it out. I need to double check the model information of some of the other devices we have tried, but they do cover a range of Android/iPhone editions. Any ideas of things to try/extra information that could be helpful would be very appreciated. Screenshot from RD client: