CrazyTux left a comment (kamailio/kamailio#4157)
If you can reproduce, can you look inside topos_t and topos_d tables to see if there are records corresponding the the call-id?
I guess Kamailio A and B are using different storage system for topos (not a shared/same database backend).
They are using separate REDIS instance backend. I will check this table and update shortly.