Balance 20X IP Passthrough - DHCP expires ~ 10 seconds

All,

I’m relatively new to Peplink devices, but we have a Peplink 20X (firmware 8.1.1 build 4990) using only Cellular WAN with IP Passthrough (now called Drop-In Mode?) enabled and connected to a Fortigate 40F (firmware: v7.0.2 build0234). The Fortigate system event log indicates a “DHCP client lease granted” from the Peplink every 10 seconds. It appears the lease expiration from the Peplink is 10 seconds (although the Peplink’s pop-up help says the DHCP lease time will be 2 minutes).

Although it’s not causing any specific problem that we can identify, we have experienced some instability and are suspecting this short DHCP lease time may be related.

Couple questions: 1) anyone else experience this behavior? 2) is there a method to change the lease expiration on the Peplink? 3) would anyone recommend setting the Fortigate to the static IP offered by the Peplink (I saw a reseller make this recommendation in an online KB)? 4) Any other suggestions?

lease expires: Thu Dec 2 13:35:53 2021
lease expires: Thu Dec 2 13:35:43 2021
lease expires: Thu Dec 2 13:35:33 2021

Thanks for any assistance.