Need help on VPN not working

My company have a, b, c, d 4sites, b,c,d already connected with VPN tunnels

I add A yesterday, connected with a 5g router, means double NAT, I know it will be some trouble

Now, A is connected with c, d but not b. Both A and B can connect C and D

Only vpn tunnel between a b is up and down, up again and down again, totally failed

Both sites use 1570, I checked all setting but no ideas why?

Any hints? is the 5g router a big problem?

I tried 5g router before on other sites, no problems at all only A site failed.

Is phase 1 coming up?

Did you put the natted addresses in the encryption domain?

Also make sure your nats are above any no nat rules might be causing issues.

What does the logs show?

Make sure you have the network between the router and the check point (when at the double NAT) in the encryption domain(s).

You need to configure a dial up connection.

You need to configure the VPN sites in b, c, d as “Only remote site initiates connection”.

After that A site is going to be connected.

Thank you, I cannot login router because it is ISP premise, I will call them to show me.

The log show nothing about these 2 sites communication, even hand shake packets.