I’ve been a bit of a headphone geek for years. I’m not sure how far down the rabbit hole you want to go, but there’s a ton of info out there and it’s just about equal parts science, snake oil, and personal preference. On the science side, every headphone is tuned to try to match a desired frequency chart by the manufacturer. Obviously material expense, manufacturer’s goals, and manufacturer’s skills all play a role. Here’s a graph from DIY Audio Heaven showing how we hear various deviations in frequencies:

There’s a bit of a divide between realistic and idealistic headphones. Realistic headphones, like studio headphones, attempt to present the music in a way that’s perceived without any additional coloring (this isn’t actually completely flat as manufacturers compensate for how our ear shape applies gain to certain frequencies), while idealistic headphones try to match a specific frequency curve such as Harman, V-shaped, etc. Many people actually find studio headphones to be a bit boring and flat to listen to, especially at first as @judddanby pointed out. Studio headphones are not attempting to match a curve that we perceive as “musical,” but are intended to be a realistic baseline for engineers to mix to, and musicians to record to.
It’s ok if you find you don’t actually like “studio” headphones! Your Beyers are studio headphones, so if you aren’t used to listening to flat headphones, you may find them lacking excitement or musicality. That’s by design. Maybe try some aiming for a Harman neutral, slight V-shape, warmer, etc.
When shopping, be as specific as possible about your needs. For example, I do a lot of transcribing, so I’m often wearing my main headphones for long periods of time. That means no IEMs or headphones that weigh over 450g. I also wear glasses, so the ear pads have to be comfortable and the clamping pressure can’t smash my frames between my ear and head. Soundstage is important to me for transcribing ensembles, as tracking where a certain instrument appears in the mix is helpful. (I have some good closed-back and IEMs for travel too.)
I’m happy to recommend other headphones or DACs, but the best way is to test some out if possible. I have no idea where you are located, but if you can get to a store where you can listen to a variety of headphones using the same few reference tracks, I’ve found that to be really helpful.