sysDescr looks ok
Getting OID .1.3.6.1.2.1.1.1.0: Executing SNMP GET of .1.3.6.1.2.1.1.1.0 on 835-VALD-WebMon
=> [b'WebMon Matrix'] OCTETSTR
b'WebMon Matrix'
Looks like the OID 1.3.6.1.4.1.994.3.4.7.17.1.68.3.0 is not found
Getting OID .1.3.6.1.4.1.994.3.4.7.17.1.68.3.0: Executing SNMP GET of .1.3.6.1.4.1.994.3.4.7.17.1.68.3.0 on 835-VALD-WebMon => [None] INTEGER
Can you do a manual snmpwalk over the relevant OIDs please? Maybe you can try this with only sysDescr and if this works add your other OIDs back.