There exists a paradox alright.
“How does such a big brain become so utterly confused ?” !!
You premise a paradox exists with example of time travel - acknowledging such an event is impossible ...but we’re to imagine it is in which a paradox exists?
A paradox is an apparent contradiction of two verifiable observations.
Finding paradox’s in the imaginary world is quite a waste of Time - don’t ya think?
Also this is getting kinda off topic...