Strange Bug

I ran into an odd bug today. I'm not sure if it is RDi, Windows, or a
combination. I'm not looking for a solution as it is easy to work around,
but it was so odd and specific I thought I would share.
Rdi: 9.6.0.4
Windows 10
(2 monitors. A = landscape, B = portrait)

Now the conditions in order to replicate took a bit to figure out.
I found that if I have my main Rdi workspace on monitor A. And drag two
or more program sources into separate windows onto monitor b. (problem
didn't seem to occur with only one source).
and then working on a display file in the main workspace, if I go to the
properties tab of a field, and select one of the drop-down options (Usage,
Type, Shift) that the drop-down menu doesn't show up on the screen. I
thought at first it wasn't actually loading, however, if I clicked where
the drop-down would have been, it would change the selection to what would
have been there. So it is as if the drop-down is invisible. If I drag
one of the source files in a separate window from Monitor B to Monitor A,
the drop-down then appears normally.

Now if I reverse things and put the main workspace on monitor B and the
other source windows on monitor A, the drop-down appears, but it appears
with a different font/look to it and not in the correct 'location' of the
screen. Again, just like the other situation, if I move a source over to
this monitor or only have one open on the other monitor, the drop-down
looks normal and is in the correct location.