jrozhon left a comment (kamailio/kamailio#4102)
Sorry, for a late response. In the meantime, I dug into the issue and it turns out that my problem is related to an issue with database connection pooling rather then presence module, although all crashes appeared only when I enabled the presence module. In the backtrace I noticed recurring reference to postgres connection, so I am trying to investigate in this direction.
Sorry for the misleading information (at least as it seems to be now).