Dog hiding under the bed

I have a male, neutered, black lab/blue heeler mix that I got from a shelter when he was about 2 months old. He is about 2 years old now. He is a bit of an anxious dog. He does not like loud noises.

I crate trained him since he was a pup, and he loves sleeping or laying in his crate. However, he has recently started laying under the bed instead of his crate. Initially, I wasn't very concerned. I am now concerned because the behavior has become more consistent. This all started because I am packing for a move, and got rid of some stuff that was under the bed. The space opened up, and he slowly moved in. In the past he would normally sit with me while I'm working on the couch or watching a show. But, during the recent batch of consistent thunder storms and the fire works he has retreated under the bed every night.

I assumed this behavior would pass, but tonight he was crying and pawing to get into the bedroom. He wanted to go under the bed. I shut the door before he could enter because I wasn't sure whether I should be enabling this behavior. I don't think he is injured. He is fine during the day. He goes for walks, runs around, and plays with his doggo friends very well. He really just does this at night. I'm not sure if he is anticipating the loud noises now and is instinctively retreating under the bed.

Should I be concerned about this behavior?