@dlakelan @dlakelan @eduperez , Thanks guys !
@dlakelan, just to answer your question, my hosts on the LAN can ping ULA addresses.
The issue is with 2XXX public IPv6 addresses,
I am trying to test hop by hop, where is it losing
OUT PACKET,
My LAN HOST => My OpenWRT(Relay Mode) => My ISP Router => Destination
IN PACKET
Source => My ISP Router => My OpenWRT(Relay Mode) => My LAN HOST
The routes are correctly advertised on my LAN host