It is common for non-mathematicians to try to deny this. Sometimes they give arguments like saying that Goedel proved that mathematical truth is not possible. Goedel would never have agreed to that.
Mathematician Timothy Chow writes:
I would say that virtually all professional mathematicians agree that questions of the form “Does Theorem T provably follow from Axioms A1, A2, and A3?” have objectively true answers. ...That is correct.
On the other hand, when it comes to the question of whether Axioms A1, A2, and A3 are true, then I think we have (what I called) “pluralism” in mathematics.
There are some axioms for the existence of very large cardinals, and some disagreement among mathematicians about whether those axioms should be regarded as true. But there is not really any serious disagreement about the truth of published theorems.
Other fields, like Physics, are filled with disputes about what is true.