pfsync and redirection of packets

[jinxray]

Im facing problem with returning traffic from service. Some diagram displayed on screen.
Problem in this specific situation: when traffic goes through opnsense-1, there is no problem and opnsense-1 know about this state. When it comes through opnsense-2(secondary, slave), tcp SYN ACK comes back only through opnsense-1, and it doesnt know about state of opnsense-2
There is no way to realize standart HA CARP+pfsync due to cloud platform architecture. Despite that I can use PFSYNC, but cant understand how to understand, if it works. Will be nice to have step-by-step instructions to perform PFSYNC between ngfw-s

[jinxray]

bumping