I loath to state the obvious since I'm fearing you are simply gaslighting.Noticed how you kept using this "private citizen" Trump BS, when once a President, always a President, just in the former sense of the title. Try harder
The whole premise of the founding of the country is based on the idea of electing leaders who serve for a time after which the become normal citizens again. The idea that a person can be elected to the presidency and retain protections from compliance with laws is precisely why the founding fathers revolted.
So again what law exactly do you base this kind of immunity on?