Pepwave Max BR1 Pro 5G.
After upgrading firmware from 8.4.0 to 8.5.1 the device no longer connects to cellular network. We are using physical SIMs.
Downgrading back to 8.4.0 solves the problem but we cannot stay on 8.4.0 long term.
Has anyone else experienced cellular connectivity issues on 8.5.1 and knows how to address them?
That’s a curious one. We have a number of them out in the field and I just traveled across the USA and back with my personal BR1 Pro 5G. Worked splendidly with 8.5.1 (AT&T; physical SIM.)
If you don’t receive an answer better than mine (I hope you do) I’d suggest submitting a ticket.
Hello @bartek (& welcome to the Peplink Community Forum),
We’d recommend ensuring you have updated the Cellular chipset firmware; this is done separately from the Router firmware and can be done from the router’s hidden engineering “support.cgi” page or via the Peplink InControl2 management platform.
If you need guidance, the Peplink Partner from whom you purchased your routers should know how to do this.
Happy to Help,
Marcus 
One question: What is the exact model number of your device. (There are at least two as there are two different modems in this model.)
Thanks both for your replies.
@mldowling I checked the cellular module firmware and it is up-to-date, version RM520NGLAAR01A08M4G_01.200.01.200.
@Rick-DC The product code is MAX-BR1-PRO-5GN-T-PRM.
OK, that’s the one with the Qualcomm X62 in it. Your experience is not expected. Frankly, I’d submit a ticket here referencing this thread. Include a diag report and turn on RA. I’d also post the ticket number in this thread.
When the issue is resolved (and it will be), please let us know what was found.
Thank you, I submitted a ticket referencing this thread. I will update the thread when I hear back from support.
The support team was able to resolve the problem. It turned out that the device did connect but it took a long time - in our tests usually around 15 minutes instead of the usual 1-3 minutes. Here’s their explanation of what was happening and how to fix it:
Since you have InControl 2 management disabled the device cant reach our servers and check Peplink eSIM status and since it was in priority 1 it was stuck in connecting status. So (…), set it to priority 2 or just disable it all together. This checking mechanism was introduced with 8.5.1 release.
Thank you for returning and letting us know what the solution was.
So, do I understand correctly that this issue should be limited to eSIMs furnished by Peplink?
We use physical SIMs, we do not use Peplink eSIMs. My understanding is that the problem was that even though there was no eSIM, the device still tried to check its status (a new feature introduced in 8.5.1).
The solution was to disable the eSIM altogether.
In general, I wouldn’t disable the Peplink eSIM, that way if you are in trouble and need it you don’t need to make modifications to the device in order to get the device back online. If you leave it enabled, you can simply put it in a lower priority via the local interface configuration page.
That’s good advice. We have easy access to the device so we don’t care but for most users it’s probably better to do as you say. That is also what the support team suggested.
I recently updated both the device firmware and the cellular module firmware, and now I am unable to connect to the cellular. I tried downgrading the firmware but that didn’t work.
@locust.ermine9580 : You double-posted. I responded to you here.