Agree - at a high level anyway- with Holmz. regardless of whether there is a benefit to break-in over time, for electronics, it's icing on the cake. I design the stuff. I hear brand new equipment literally all the time. Its fine. Maybe not optimal but fine.
Speakers do require some break in, or did, since mechanical bits need to break in (mechanical stuff, sometimes its glue and other stiffeners, etc. - not my thing).
Warm up is quite critical for some amps but should be complete within 24 hours (if always on) and the vast majority accomplished within an hour or three.
I would check hook ups. the other day I sat down at a friend’s with a prototype and immediately said "somethings out of phase". It was an interior connector on my preamp - my fault. But blatant. He missed it.
I’d also consider something just plain defective. But what?
Agree the litany of conditioners, wires, and magic incantations - even if they sometimes matter- are not at the heart of first order problems.
Start sleuthing.