Check internet Access on Dual WAN - failover with pcc

Hi,
i have Dual Wan Load Balancing (Failover with pcc)

Problem :
When an Internet connection is discontinued due to the amount of traffic being terminated, that connection will not be cut off and will continue to be sent to the same Internet service packet which will result in the user’s lack of access to the Internet.

Wan1 is a ADSL modem = connected to MT (but not have Internet Access)
user1 → MT → WAN1 → fail
user2 → MT → WAN2 → OK