Normally the shield is not attached to the xlr connectors on mic cables.
Since when?
Here's some info from the following link regarding not connecting the shield:
http://www.taperssection.com/reference/pdf/DIY_CableDiagram_Rane.pdf"A common solution to these noisy hum and buzz problems involves disconnecting one end of the shield, even
though one can not buy off-the-shelf cables with the shield disconnected at one end. The best end to disconnect
is a matter of personal preference and should be religiously obeyed; choose inputs or outputs and always lift the
side you choose (our drawings happen to disconnect the input end of the cable -- the output of the driving unit). If
one end of the shield is disconnected, the noisy hum current stops flowing and away goes the hum -- but only at
low frequencies. A one-end-only shield connection increases the possibility of high frequency (radio) interference
since the shield may act as an antenna. Many reduce this potential RF interference by providing an RF path
through a small capacitor (0.1 or 0.01 microfarad ceramic disc) connected from the lifted end of the shield to the
chassis. The fact that many modern day installers still follow this one-end-only rule with consistent success
indicates this and other acceptable solutions to RF issues exist, though the increasing use of digital and wireless
technology greatly increases the possibility of future RF problems.
If you've truly isolated your hum problem to a specific unit, chances are, even though the documentation
indicates proper chassis grounded shields, the suspect unit is not internally grounded properly. Here is where
special test cable assemblies, shown in Figure 3, really come in handy. These assemblies allow you to connect
the shield to chassis ground at the point of entry, or to pin 1, or to lift one end of the shield. The task becomes
more difficult when the unit you've isolated has multiple inputs and outputs. On a suspect unit with multiple
cables, try various configurations on each connection to find out if special cable assemblies are needed at more
than one point."
FWIW, the BBee's I owned did have the shield connected to the xlr on both ends. I think the only time you see it not connected is in an unbalanced cable, but YMMV.