ssh broken pipe

[oodsway]

I keep getting broken pipe when ssh into pfSense on my LAN. It began after I upgraded OS from Kubuntu 16.04 to 18.04 when I was still on pfSense 2.4.3-release p1. While on 16.04, I could remain logged in all day. Yes, I have experimented with settings on my /etc/.ssh/config as well as /etc/ssh/sshd_config on pfsense.

Last week I upgraded to pfSense 2.4.4 and noted that the issue disappeared only to reappear today. These are my ssh settings:

/etc/.ssh/config
Host *
# TCPKeepAlive yes (makes no difference)
ServerAliveInterval 120
ServerAliveCountMax 720

pfSense
/etc/ssh/sshd_config (all other default settings omitted)
ClientAliveInterval 120
ClientAliveCountMax 720

I tried configuring ssh with id_rsa.pub but this didn't help either.

I should add that I'm typically running tcpdump while ssh. Usually I am monitoringt DNS on port 853 or for pfBlockerNG activity.

I appreciate any help.

Forgot to add, that I can ssh into other systems and remain logged in for the entire day without getting the broken pipe. Broken pipe ONLY happens ssh to pfSense.