Updates can fail for many different reasons. Can you share more information about your deployment size, if you have HA and Public access?
Are both Admin and IRP VM on the same ESXi host?
Is IRP VM on a DMZ network or the same network where Admin VM is located?
Is ICMP protocol enabled in the DMZ firewall to allow ping between Admin and IRP VMs?
Do you get an issue with ISO update file validation, or the actual update fails?
Have you tried restarting both Admin and IRP VM and trying the update to 188.8.131.5239 again?
There are no known issues with the update from 184.108.40.206 to 220.127.116.1139, so it might be the ISO, connectivity with the IRP VM, times being out of sync.
If you verified all the requirements are fulfilled and it still fails, open a ticket with TAC to take a look at the minorUpgrade.log and yumUpgrade.log files on both Admin and IRP VMs to identify exactly what is happening.