When using the Firefly backend for lsst.afw.display, the first MaskedImage or Exposure displayed via Display.mtv has a wonderful mask overlay (much better than DS9's!).

Unfortunately, if I call mtv a second time on the same Display instance, the mask overlays do not appear, even though the image itself is updated.

If I close the image window in Firefly itself before calling Display.mtv, things work as expected.

If a quick fix is possible, it'd be great to get it in this week so I can avoid demoing the workaround at LSST@Europe3 next week (but it's not a terrible workaround if quick fix is not possible).