FVX538 dual-port problem

I have the following issue

WAN1 I have connected to an ISP which is PPPoE dial, just connect in the WAN2 port another ISP that uses IP, at this point I have no problem, 2 suppliers connect correctly.

The problem arises when configuring Load Balancing or Auto Rollover, I explain each case.

Load Balancing: If I configure load balancing, and one of the two ISPs disconnected due to failure of service, I was completely without internet, no browsing, no Email, the Internet nothing works no matter if the second ISP is running and connected. When service is reestablished from the first ISP, FXV538 does not reconnect automatically, I have off and on directly or reboot.

Auto Rollover: If I have configured the auto rollover and the first ISP disconnected due to failure of service, the FVX538 does correctly change to the second ISP, but when service is reestablished from the first internet provider and detects FVX538 the connection, I get disconnected from the second ISP, but I stay completely without internet, I have to reboot or power cycle the FVX538

Hopefully you understand my problem, I'm from Mexico and my English is not very good

Would be very appreciated that someone can help me with this problemshould be mentioned that just update the firmware to 3.0.6 - 25

My FVX data are as follows:

Firmware version (Primary) 3.0.6 - 25
Firmware version (Secondary) 2.1.0 - 7

Thanks in advance