LLDP neighbor information not available via SNMP in Observium

For Huawei switches S6700 series the lldp neighbors cannot be seen in Observium.

The iso MIBs are enabled on the switch, see https://support.huawei.com/enterprise/en/doc/EDOC1000178174/b81cd830/why-the-lldp-neighbor-information-cannot-be-obtained-through-snmp-or-the-operations-performed-on-lldp-mib-objects-do-not-take-effect

If I use snmpwalk on the Observium Host I can get the information:
observium# snmpwalk -v2c -c public device_VN .1.0.8802.1.1.2.1.4.1.1.9
iso.0.8802.1.1.2.1.4.1.1.9.0.1.1 = STRING: “device_SN"
iso.0.8802.1.1.2.1.4.1.1.9.0.2.1 = STRING: “device_SN"
iso.0.8802.1.1.2.1.4.1.1.9.0.50.1 = STRING: “device_VR"
iso.0.8802.1.1.2.1.4.1.1.9.0.52.1 = STRING: “device_EF”

<device_VN>display version                  
Huawei Versatile Routing Platform Software          
VRP (R) software, Version 5.170 (S6730 V200R024C00SPC500)

Attached is the output (redacted) of

./discovery.php -h device_VN -m neighbors -d
./discovery.php -h device_VN -m mibs -d