For the below errors:

[root@psql02 log]# showmount -e nfs02
rpc mount export: RPC: Unable to receive; errno = Connection refused
[root@psql02 log]#

Apr 16 01:12:37 nfs02 kernel: FINAL_REJECT: IN=eth0 OUT= MAC=00:50:56:86:2d:21:00:50:56:86:3c:c7:08:00 SRC=192.168.0.124 DST=192.168.0.119 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=44729 DF PROTO=TCP SPT=978 DPT=20048 WINDOW=29200 RES=0x00 SYN URGP=0

[root@nfs02 log]#
[root@nfs02 log]#
[root@nfs02 log]#
[root@nfs02 log]# firewall-cmd –zone=public –list-all
public
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: haproxy
  ports: 20048/udp 2049/tcp 111/tcp 111/udp 24007-24008/tcp 38465-38469/tcp 4501/tcp 4501/udp 22/tcp 22/udp 49000-59999/udp 49000-59999/tcp 9000/tcp 9000/udp 137/udp 138/udp
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:

[root@nfs02 log]#

Ensure you have port 20048 TCP added to your firewall:

  995  firewall-cmd –zone=public –permanent –add-port=20048/tcp
  996  firewall-cmd –reload

Cheers,
TK