VoLTE calls cannot be established successfully

[ggsnpdsn]

VoLTE calls cannot be established successfully. I'm using the custom_deployments\open5gs_hss_cx\4g-volte-deploy.yaml and custom_deployments\open5gs_hss_cx.custom_env files. Here are the logs:
Open5GS daemon v2.8.0-48-gf87da61

08/08 08:29:22.792: [app] INFO: Configuration: '/open5gs/install/etc/open5gs/hss.yaml' (../lib/app/ogs-init.c:144)
08/08 08:29:22.792: [app] INFO: File Logging: '/open5gs/install/var/log/open5gs/hss.log' (../lib/app/ogs-init.c:147)
08/08 08:29:22.795: [metrics] INFO: metrics_server() [http://172.22.0.3]:9091 (../lib/metrics/prometheus/context.c:392)
08/08 08:29:22.842: [dbi] INFO: MongoDB URI: 'mongodb://172.22.0.2/open5gs' (../lib/dbi/ogs-mongoc.c:128)
08/08 08:29:22.931: [app] INFO: Polling freeDiameter stats every 60000000 usecs (../lib/diameter/common/stats.c:77)
08/08 08:29:22.932: [app] INFO: HSS initialize...done (../src/hss/app-init.c:31)
08/08 08:29:22.934: [diam] INFO: CONNECTED TO 'mme.epc.mnc001.mcc001.3gppnetwork.org' (SCTP,soc#16): (../lib/diameter/common/logger.c:81)
08/08 08:29:39.315: [diam] INFO: CONNECTED TO 'icscf.ims.mnc001.mcc001.3gppnetwork.org' (TCP,soc#13): (../lib/diameter/common/logger.c:81)
08/08 08:29:39.458: [diam] INFO: CONNECTED TO 'scscf.ims.mnc001.mcc001.3gppnetwork.org' (TCP,soc#17): (../lib/diameter/common/logger.c:81)
08/08 08:30:55.578: [diam] ERROR: pid:PSM/mme.epc.mnc001.mcc001.3gppnetwork.org in fd_psm_change_state@p_psm.c:284: 'STATE_OPEN' -> 'STATE_CLOSED' 'mme.epc.mnc001.mcc001.3gppnetwork.org'
((null):0)
08/08 08:31:07.888: [diam] ERROR: pid:PSM/scscf.ims.mnc001.mcc001.3gppnetwork.org in fd_psm_change_state@p_psm.c:284: 'STATE_OPEN' -> 'STATE_CLOSED' 'scscf.ims.mnc001.mcc001.3gppnetwork.org'
((null):0)
08/08 08:31:07.923: [diam] ERROR: pid:PSM/icscf.ims.mnc001.mcc001.3gppnetwork.org in fd_psm_change_state@p_psm.c:284: 'STATE_OPEN' -> 'STATE_CLOSED' 'icscf.ims.mnc001.mcc001.3gppnetwork.org'
((null):0)