Hello Lopephish,
I did not meet this issue but I remember getting a similar issue with some old build of VirtualDJ, when pressing on the Fast Forward keys, I could get the fast forward keeping on while I had released the key.
1) What is your version of VirtualDJ ? Are you on Mac or PC ?
2) To know whether it comes from the D controller or from the DJ, can you try mixing on the Rmx with Djuced ( https://www.djuced.com/downloaddjuced/ )?
- If you get also this issue in Djuced, it probably comes from the controller,
- if you cannot get this issue in Djuced, it probably comes from the software.