Gah, just yesterday I had this crazy problem with SSH tunnels and psql (Postgres client) crashing the tunnel. What solved it? Changing my interface MTU... http://www.snailbook.com/faq/mtu-mismatch.auto.html
This is interesting. I sometimes have to connect to a VPN that crashes when something provokes a burst of activity (if I cat a file or even ls a large dir). I'll try this, but 576 seems so low; how did you get at this number?
I remember as the average packet size on the internet. Googling average packet size yields that- https://etherealmind.com/average-ip-packet-size/