I don’t think that congressmen are subject to perjury for anything they say in the Capitol. This was put into the constitution as a protection of free speech for our legislators in carrying out their duties. The founders never dreamed there would be such extreme dishonesty and corruption as we see today.
I could be wrong, but I think that a congress critter can say anything they want to only on the House floor and get away with it.
That would not include in a hearing where a House member has been sworn in.