Floating PING rule not reaching target

[Operations]

I have a external IPv4 address from my ISP (WAN) and i have got an extra external IPv4 /29 subnet through a GRE tunnel.

My question is simple i think. When i setup a IPv4 ICMP (echorep, echoreq) allow all on the Floating Firewall, i am seeing the ping come i but my cloud/unifi at ..*.211 and 212 (both from the extra IPv4 subnet) do not respond.

When i set the same ICMP rule on the Extra IPv4 subnet Firewall i am getting a reply to my ping. Why is floating ping rule not working for this extra subnet? The floating ping does work on the WAN IP from ISP.

It is not a major issue and i have a solution, so just wondering. And i know it is not recommend to allow PING on IPv4, but something it serves a purpose.

[Operations]

No ideas?