FDB entries missing for Dell S-Series OS10EE

Hello,

we use Observium in the professional edition, are very satisfied!
Unfortunately the FDB feature we often use, delivers incomplete results for our new Dell switches:
For Dell S-Series 5248F and 5232F only 9 entries are displayed in the FDB. For S4112F switches only 4 entries.
Normally there should be about 2000 MAC address entries.

We use Dell OS 10 Enterprise Edition Version 10.5.0.3.

With our Brocade switches and Dell N series OS6 everything is fine.
Can you please take a look at the error?
Attached the poller debug for dell s5248f switch (abaout 2000 MAC addresses in MAC address table, 9 entries in Observium FDB).

Thanks and best regards
Frank Malisius

-- 
---------------------------------------------------------------
 Dipl.-Ing. Frank Malisius
 Gemeinsames Netzwerkzentrum (GNZ) der Berlin-Brandenburgischen
 Max-Planck-Einrichtungen am Fritz-Haber-Institut der MPG
 Van't-Hoff Strasse 19
 14195 Berlin
 Germany