Hi Rayne,
welcome to the Onyx community, it’s great to have you!
The overspecification-test works numerically, so with complex models (and yours seems to be in view of 435 observed statistics :), it does happen that the warning is really nothing more but a warning, and the model is absolutely find. However, it can also happen that the model is empirically overspecified. Could you maybe send me the .xml file of the saved model? Then I could simulate some data and check whether I see where an overspecification may be burried.
Cheers,
Timo