Please restart PokerTracker 4 using the logging enabled link on your Start Menu, reproduce this problem and then report it via our support system with the log file so we can see what's going on here. You can access the log file by clicking 'File --> Show User Data Folder' in the main PokerTracker 4 window - the file we need is the text file called 'PokerTracker4.log' that is in that folder:
I do not see a support ticket from the OP so can you please open a ticket with a PokerTracker4.log file that's recorded the trouble so we can investigate this for you.
If you are playing FastForward then we pushed a fix yesterday, and that will be downloaded automatically when you restart PT4 (also close Party Poker down whilc you restart PT4). If you're still having problems after restarting both Party and PT4 please do open a support ticket so that we can see what is going on.