FSUIPC key map issue

I've posted over on the QW support forums (two months back) with no response to date so looking for some advice here related to FSUIPC.

In their 787 (v4) I am able to use the keyboard assignments to activate external lights (strobes, nav, turnoff, etc). However, if I use FSUIPC to map a switch to this very same assignment in the sim I can see the switch "jump" for a nanosecond, hear the sound, but the lights don't activate.

I've confirmed there is no repeat set to the keys, etc. A similar approach works on other complex aircraft (all PMDG planes for example) so it seems specific to something in the way QW has coded theirs.

Essentially, while it doesn't suggest anything wrong with their product has anyone been able to work around similar behavior? Thanks!
This is not a product support forum, it is a forum dedicated to developers interacting with developers be they freeware, payware, or personalware.
And this was not a product support request but a question related to FSUIPC's interaction with the simulator in an unexpected way, but thank you for your input nonetheless.