Cannot turn HA Ap to AA

[Scoombuk]

Today tried to switch my pair of 500e’s to AA. 
they are on AP. At first the option wasn’t there. Removed some legacy wan config and there it was. 
when I select it and apply and go back it won’t stick on AA. 

any thoughts anyone?

7.4.1

[Nchandan]

You can disable A-P functionality, but you can still maintain security by setting up two firewalls. The recommended configuration in this case is to set up the firewalls as A-A, with the primary firewall having the higher priority. 

You can refer to the below document on how to setup A-A HA:

https://docs.fortinet.com/document/fortigate/7.4.1/administration-guide/357558/ha-active-active-clus...