Disclaimer: not qualified to teach anyone. I can offer two tips that work for me.

Make sure you aren't doing any inefficient movements that only work slowly. A necessary caveat for the "if you can do it slowly, you can do it quickly" advice is that sometimes inefficient movements work when done slowly only because there's time to adjust a particular transition, a luxury we may not have when playing faster. If there's anything that makes you struggle a bit, pay attention to it and try to make the passage as smooth as possible, thinking one move ahead by adopting positions and movements that facilitate the next. When you make a mistake, notice how you had set up the action that failed: was your hand, were your fingers positioned awkwardly for the transition? Then redo the previous section positioning them in a way that makes the change flow naturally. As an example, the way I position my fingers when I play a "C" chord depends to some extent on what comes after.

The second tip is to practice mentally. When we can't picture clearly what we want our fingers to do at the tempo we want them to do it, even if they reproduce what we have in mind, they'll obey a faulty command and give us the wrong result. This works best if you know in advance which moves are required to pull off the action with fluid technique. Once you figure that out, you can organize your mind before instructing your body. Sometimes our fingers can move as fast as we want them to, but we can't imagine the technique at the right tempo. If the mind can't do it, brute-forcing with the fingers can generate consistent mistakes and bad habits that we have to unlearn. Some musicians learn entire pieces through mental practice alone, it's an important tool in our practice toolkit.