Razer Basilisk Mobile - Side Button (shift, ctrl) not working

https://preview.redd.it/0wvbxbi3cffg1.png?width=744&format=png&auto=webp&s=0202d636aff17a48de9865447347fdbcd528be80

Im wondering if someone knows of a solution for this. Im a casual gamer (WOW) and I have always used a combination of Mouse Button 4 & 5 with my Shift & Ctrl keys to be able to keybind 6 additional spells etc.

I was hoping that I could keybind the third side button (see screenshot F16) on my Razer Basilisk Mobile and do the same but unfortunaley it will only accept in game (and out of game) the one command; it does not understand/allow Shift or Ctrl etc. I tested in other games like LOTRO and its the same result.

I did some messing around and assigned Mouse Button 5 to the third side button instead and the game understood the commands just fine with using Shift or Ctrl, so the button is capable of doing it.

Razer if you see this can you just patch in a Mouse Button 6?! I have a feeling that is the only REAL solution to fixing this problem!

One other thing thats seems add to me is the third side button (in this case F16) wont work until I completely exit synapse on my computer. Then it seems to work just fine in game and out of game. (would have thought it be the opposite from other the post I've read)

Anyways, in the mean time any advice or tips would be greatly appreciated!

Thanks