In this rousing sequel to Kickboxer, Tong Po broods about his defeat at the hands of Kurt Sloan. Po and his managers resort to drastic measures to goad Kurt's brother into the ring for a rematch.
I didn't even know they made a sequel until it came on Amazon Prime... and I can see why. No van Damme. Sure, it has Sasha Mitchell, but no one knows who he is and really most people care about him even less than they do van Damme.
The real flaw, however, is the plot. Sasha is drawn back into competition to save the dojo. This is a problem because, well, we have seen this plot a thousand times over and it's just as interesting as all the other times we have seen it and far less interesting than when it was original and not a trope.
So, you have a plot that you have seen before and a sequel that doesn't have the original star. Of course it's doomed for failure.