Ping is failing to IRB as there is no ARP entry after Junos upgrade from 18.2 to 21.3.
Remove "evpn no-arp-suppression" knob.
The no-arp-suppression statement is no longer supported starting in Junos OS Release 19.1R1:
https://www.juniper.net/documentation/us/en/software/junos/evpn-vxlan/topics/concept/evpn-proxy-arp-support.html
NOTE: In Junos OS Releases prior to 19.1R1, you could turn off the suppression of ARP packets and NDP packets by specifying the no-arp-suppression configuration statement. However, installations nearly always need ARP suppression and NDP suppression to remain enabled. As a result, the no-arp-suppression statement is no longer supported starting in Junos OS Release 19.1R1. The statement has been deprecated.