Try adding a 4 ohm resistor between the x-over tweeter output and the tweeter. That seems to level it off nicely in XSim. More (or less) might be necessary, since the values of the compnents aren’t marked, and I really didn’t trace the board out to see how it was all connected. It’s at least a start. You can fine tune it by ear to suit your taste.
You could also try “flipping” the tweeter connections; instead of + to + and -to -, try + to – and – to +. It all depends on which way you like it.