Mirroring Decals in Flamingo 5.5

I work with ships so everything is pretty much bilaterally symmetrical. I recently upgraded to the latest Rhino and Flamingo. When applying decals on both port and starboard sides, I would place all the decals on one side, and then simply mirror those objects off the centre line and then in the decals properties, mirror the decal. It would ensure perfect symmetrical placement and save me a bunch of time.

Now when I mirror an object (like a surface for example) with a decal on it, Flamingo 5.5 only renders the decal on the wrong side, even if I have direction set to ‘both’. Plus there is no ‘mirror’ button to be found. The built-in Rhino render engine behaves as previously so this seems to just be a Flamingo issue. Thoughts?

Rhino rendered view:

Flamingo render: