Sophos UTM incorrectly discovered as Generic Linux device

Hi everyone, I’m having a bit of trouble getting a couple of Sophos UTM devices to be discovered correctly in LibreNMS.

We previously had an SG650 and SG450 appliance monitored which has been working fine for a couple of months, however when I have added in our new SG550 appliance too, things seem to have taken a strange turn. The SG550 and SG450 are no longer discovered as Sophos devices and just show as Generic x86 64-bit devices, and the previous SG650 appliance has stopped collecting port data.

So far I have tried to re-discover the devices and also deleted and re-added one of them to try and fix the issue but it doesn’t seem to have made a difference.

Here is the output of ./validate.php:

$ cd /opt/librenms
$ php validate.php
====================================
Component | Version
--------- | -------
LibreNMS  | 1.56-9-gbe0438813
DB Schema | 2019_10_03_211702_serialize_config (144)
PHP       | 7.2.19-0ubuntu0.18.04.2
MySQL     | 10.1.41-MariaDB-0ubuntu0.18.04.1
RRDTool   | 1.7.0
SNMP      | NET-SNMP 5.7.3
====================================

[OK]    Composer Version: 1.9.0
[OK]    Dependencies up-to-date.
[OK]    Database connection successful
[OK]    Database schema correct

Is there something else I need to do, or can I force a device to be discovered as a certain type?

Thanks
Gary

edit: I’m thinking this is possibly caused by a change to the SNMP for the UTM in an update?
The only differences I can see with the two affected devices is that their firmware version is 9.605 and the other one that is still working is on 9.601.

Any help would be much appreciated, as I’m not sure how to get them to be discovered properly in LibreNMS

Thanks
Gary