There has been greater scrutiny in the last five months, so traveling together is a good idea, even for domestic flights. My husband (Brazilian, and a US citizen since 2023) and I (US citizen since birth) were returning from a trip to Brazil in February, sailed through immigration in Atlanta (we went to the officer together), and when we were exiting the baggage area, a CBP officer asked my husband if he was traveling alone. I heard the question and replied, "we are together;" he saw me and let us through with no further questions. If my husband had been alone, the officer would have likely questioned him, searched his luggage, etc.