@miconda not sure if it's useful but i tried to start kamailio with the mentioned route_locks_size but could not get it up (tried with values 1,2,8,16,20).
``` Starting Kamailio (OpenSER) - the Open Source SIP Server... Feb 01 09:47:57 ifens224 kamailio[11130]: INFO: pv [pv_shv.c:60]: shvar_init_locks(): locks array size 16 Feb 01 09:47:57 ifens224 kamailio[11130]: ERROR: <core> [core/receive.c:82]: ksr_route_locks_set_init(): failed to allocate route locks set ```