Dear @Matheus.Abreu,
When you enable both PtfmYDOF and YawDOF in ElastoDyn, it is necessary to set PtfrmYIner nonzero as discussed in the following forum topic: Wind Veer Parameter - #52 by Andre.White. It is not necessary to set PtfmRIner and PtfmPIner nonzero because roll and pitch motion of the platform will not have zero inertia.
I’m not sure why your model is diverging. What did you change relative to the OpenFAST model available in the r-test?
Best regards,