Mentioning previous answers is just a convenience. It should not discourage follow-on questions, information, or debate.

There was some discussion recently in "During the American Civil War, what happened to the sitting Representatives and Senators of the seceded Southern states? Did they resign their offices, or maintain them?" at https://www.reddit.com/r/AskHistorians/comments/7xdahg/during_the_american_civil_war_what_happened_to/ .

/u/freedmenspatrol covered it in a top-level comment, that a few members of Congress from seceded states stayed in Congress after their secessions.

The reply to that disagrees with "They resigned...mostly" on the technical details. At least in the Senate, those who made statements about withdrawing before the end of the term on 4 March 1861 apparently were eventually deemed to have resigned, those from states that seceded later but made no statement (just didn't show up for work) were expelled, and those whose terms expired and where there could be no re-elections were no longer members.