My tree has a clearly identified great grandfather A of my husband, plus his wife B and ancestors of both of them for a few generations.
Thrulines insist that his great grandparents could have been X and Z, plus all of their respective ancestors.
It also suggests potential ancestors when I have ruled them out for whatever reason.
I don't use Thrulines very much, I prefer to look at Common Ancestor filter, still some mistakes, but not as many - most seem plausible if not proven to my satisfaction.
Unless Sinann remembers how she got rid of her wrong suggestions, the best thing to do is just to ignore them.
As for the quote from Ancestry 'If a potential ancestor does not support what you know about your family's history, you may contact the family tree owner associated with that person to correct any errors or make changes'.
The tree they have suggested is not necessarily wrong in the first place, when Ancestry plucks it out of nowhere as a match. A and B above are not in any way connected to X and Y, but the tree with X and Y itself isn't incorrect, just the association.
Regards Margaret