We use some Chelsio T540-CR NICs and after upgrading to 11.2 from 11.1 we have run into an issue where the NICs don't forward any traffic after rebooting them. If we unplug the SFPs and then reinsert them everything will start working. Looking at ifconfig everything looks normal and ifconfig down/up does not help. The SFPs we are experiencing the issue with are 1Gbit CWDM optics, our 10Gbit DAC cables are working correctly. I'm unable to find anything specific in the log about what is happening, but interface frame counters say we are sending packets, but nothing is received at the other end and we are not receiving any thing at all according to the same counters.
Looking at the hw.t5nex.0.misc.devlog I noticed a line containing "hw_mac_init_port, …" is always logged when it works, but never when it doesn't work. Otherwise the there is not anything obvious to me in that log. (Full log can be found in the original email thread.)
After downgrading the firmware from 126.96.36.199 to 188.8.131.52 and disabling automatic upgrade in loader.conf everything works as expected, even on 11.2.
We still experience issues if we try to upgrade to the latest 184.108.40.206 firmware.