There are certain restrictions that exist when creating failover groups. One of them is that you cannot use the same circuit in multiple failover groups.Using a circuit in multiple failover groups can cause intermittent failover results.
A failover group is not working properly. The failover group may fail over; however, routes do not fail over. If a given circuit is used in more than one failover group, you may run into a scenario where the first failover group fails over, however, the second one may not. Parameters such as the OSPF cost increment value may affect this as well. Failover groups should be configured in such a way that there is no redundancy between the two groups.
In order for a failover group to work properly you can only use a given circuit in one failover group.