I agree, something for the glutes or hips or hamstrings. Something that extends the hips and makes you stand up straighter. You may need to try out a couple to find a good one.
Could be band walks, or side laying clams, or even hamstring curls.
Or something more strenuous like 45 Degree back raises, Glute/ham raises, cable pull thrus.
If you want to get brainwashed by Louie, you could try reverse Hypers and sled dragging.
This is kinda cool.
Also, if you always deadlift conventional stance, doing some work in the Sumo or “Squat Stance” can build up your hips/glutes in a hurry.