Based on the further analysis done so far by engineering, the DNS query is with opcode 0 i.e “ANY" query ( and not with opcode14) for a domain. By the time we got the response from the backend server for “ANY" query, client side pcb seems to be freed or unlinked from the server side pcb. Hence the crash is being observed. The Engineering team is still investigating the issue to determine the cause on what is causing the linked pcb to be freed up.
Will keep you updated on the progress of the case.