Hiya @C_White_SMAR welcome to Zwift forums.
What kind of bike are you using? What gearing does it have? Does it have chainrings that are substantially smaller than what you’d find on a typical road bike (50x34)?
Normally, I’d say that you should try bumping up the FTP numer in your game user profile. Raising it would have the fastest effect in fixing “resistance is too low” complaints. But you say your FTP is accurate, so maybe not? How do you know it’s accurate for this particular trainer you’re using? It’s common for folks upgrading from a wheel-on trainer to find their old FTP numberr is all of a sudden too difficult for a (more accurate) direct-drive trainer.