When you work out, do you actually feel like you engage your glutes? That has been a huge problem for a lot of my life and I believe if you have a weak posterior chain you can kinda lose the mind-butt cheek connection to get the muscles firing because then the rest of your body over compensates and kinda takes over the function of the glutes.

That being said I believe that good exercises for REALLY isolating the glutes are bridges. Make sure your abs are engaged and your tail is slightly tucked and squeeze those babies so that it feels like you're being propelled by the cheeks. You can hold weight on your pelvis to add resistance. If you feel strong enough you can do one-legged bridges as well. I think as with all exercise, though, you want to make sure you have the right form down and you're actively engaging the muscles you're trying to engage. If you're feeling the bridge in your quads/lower back, you're not doing it right.

Also I think resistance band exercises are pretty good, like doing the side to sides can help the gluteus medius I believe. I think donkey kicks are supposed to be good too. I'd also look at hip flexor exercises too as sitting for long periods shortens those muscles and I think that can also affect your glutes/posterior chain.

I hope this helps and sorry if I over explained, I just like to be as thorough as I can to make sense of things