That is what the Catholic Church teaches about Mormonism.
I might be younger than you there was a time before the 70’s when if you were baptized in another church you had to be baptized again if you changed.
and just like that along the way thie requirment has been null and void.
In the 50’s & 60’s oh the commotion in the family house holds especially those who made a big deal about it.
Protestants going to a Catholic wedding and VS or wondering about if they were going to serve alcohol or not at the events and of course trying to wrap their mind around each others customs.
Today one should try to figure out if these changes were church policy or the Lord’s doctrine.
I myself see nothing wrong with the Trinity for many still feel they are worshiping the Father, Son and Holy Ghost.
It is when the Council of Nicene 325 AD enter into this is arguement and said this is the interpretation.
Now that is 325 years after the death of Christ these man took it upon themselves to settle the dispute.
No matter how one slices it, it is still 3 personages with 3 different missions.
Anyway thank you for your civil discourse.