Slow keyboard response on High Sierra and Windows 10 (TradeStation 10 IDE)

I've not noticed this before, but after previously with the IDE, I can type at normal speed. Now somewhere along the line of Parallels update to 15, Parallels tools updates, and all that, the keyboard types at the rate of a painfully slow 1 character per second.
How to troubleshoot? Fix? Workaround?
Thanks, Caesar.

 

Other applications run just fine.