Problem about peplink 210 high availability

Since I have used two peplink 210 and set the high availability in the group ID 1.But the Wan 1 of Peplink 210 cannot ping the internet gateway. The wan 2 is OK in the same setting.
When i have changed the group ID to 80. The Wan 1 and Wan 2 will return normal.
We would like to know what are the different of the high availability group 1 with others group number.

Thank You.

Hi,

May I know what is the firmware version? Please upgrade to latest firmware version if you are using old firmware. Please download latest firmware from here.

The prplink 210 Firmware version is 5.4.10 build 1585.
Thank You.