@Lindon Firstly, I suggest you change the name and ID of the plugin and re-compile it. As I see you've already done that.
So, are there controls that change the values โโof the parameters that are isPluginParameter enabled? If yes, you should make them also isMetaParameter. Otherwise AU plugin validation fails. Maybe that could be related to VST3 too.
Other possibility is compiled custom .dll nodes. If the target value and controller value ranges are different each other, that causes crash in DAW. So make sure that parameter ranges (including the middle points) are the same.