Dual WAN NAT Port forwarding issue

[CirbyYKT]

Hi,

I have a problem with NAT Port forwarding from 2 WANs. I'm port forwarding single port to single host from 2 WANs simultaneously.

When WAN1 is up everything works fine, i can ping both WAN1 and WAN2 external address but when WAN1 goes down i can't ping WAN2 for some reason. If i switch default gateway from WAN1 to WAN2 same issue but backwards i.e. WAN2 goes down cant ping WAN1.

Attached screenshots, what am i doing wrong?

Appreciate any help.