The low bandwidth notification in spacedesk will only be triggered if it fails to receive a specific response packets/ping from the spacedesk viewer app (and vice versa).
If the notification appears on pc/server side, it means the server cannot receive a ping response from the client/viewer which means the client fails to send it (probably because there’s a network congestion on its side).
Even if the pc/server machine has low network load and currently stable if it didn’t receive the ping from client then it will trigger a temporary disconnect if it continuously showing the notification.
If the notification appears on client/viewer side, then it’s vice versa from the above explanation.
Next, can you easily try connecting via Mobile Hotspot or WiFi Direct network?
So that server and client has a direct network connection to each other and bypassing the router.
To setup, please check the Performance Tuning -> Network Bandwidth -> Wifi Direct chapter in the user manual https://www.spacedesk.net/user-manual/#item_510.
For AMD crash, can you check if there’s an error code 43 in the AMD graphics adapter in the device manager?