Hi,
Could you possibly share a more comprehensive repro of the issue such as the models that you are loading, if possible?
How did you check the shared memory limit on your machine? Does the output of  ipcs  -lm indicate that the shared memory is unlimited (this should tell you the max no. of SHM segments and max SHM size)? Also, just to confirm, have you checked if any other processes are taking up too much shared memory on your machine?
To increase the shared memory limit, you can try setting the kernel.shmmax parameter (i.e. sysctl -w kernel.shmmax=...), and follow the steps here: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/5/html/tuning_and_optimizing_red_hat_enterprise_linux_for_oracle_9i_and_10g_databases/sect-oracle_9i_and_10g_tuning_guide-setting_shared_memory-setting_shmmni_parameter to increase the # of shared memory segments available.