Razer Anansi keyboard missing letters after SHIFT key is pressed

Hello,
I have been using this keyboard since it was released and love the feel of the keys while using it, for the last couple of months though, I have been having an issue when I press the SHIFT key where it will not type the letter unless I hit the letter key twice. It is sporadic in nature so, it doesn't do it every time.

I have Synapse version 2.21 installed on a Windows 10 Pro version 2004, OS Build 19041.985.

It's starting to drive me nuts now and am not sure how to fix it, I don't really want to replace this keyboard because the layout is perfect for my playstyle. I know that it's old and I should probably move on but, would rather not..

Thanks in advance for any advice or recommendations.