I have discovered the same issue using a C5 running platform version 2.3.6.146. I have tried both 2.0.44 and 2.0.48 on the ELK M1XEP. I am using the non-secure port. Everything works pretty good, but I randomly get:
Elk M1 Telnet is restarting...
Elk M1 Telnet connection dropped...
Elk M1 telnetStatus error: receive error: Stream is closed
When this occurs I loose all messages coming from the ELK. The hub will eventually reconnect on its own. I have tested by connecting the hub and ELK on their own network to rule out network issues or conflicts. I am using Elk M1 Driver version 2.6 by Mike Magrann.