Hi Dave, I can't tell what the OIDs you are reading nor the device type/family you are looking at.
Is this a new 3rd party MIB ? i.e. one you added?
note FlexViews send the OIDs in PDU blocks if you are including OIDs in the 'default' group that are not responding at the device it may appear there is no support at all.
Verify each OID you are looking for in the FlexView is being returned by MIB Tools.
Any that are different instances other that (0 - scalars) I would move to the 2 request block using the FlexView editor.