Hi Miramar_brendan,
Thanks for posting this issue to Apple Support Communities today. It sounds like you're unable to get EQ working with your wireless headphones. I know it can be useful to modify that for different styles of music.
Have a look at Sound Check, EQ, and volume limit settings on iPhone. Have you checked for Screen Time Restrictions as described in the article? Have you tried Sound Check to see if anything changes?
You may also want to try restarting the iPhone: Restart your iPhone, iPad, or iPod touch. This can fix some minor issues at times.
Unpairing the Bluetooth headphones may help as well: Pair a third-party Bluetooth accessory with your iPhone, iPad, or iPod touch. After unpairing, restart the devices and pair them again.
You can also try testing with the Lightning EarPods that came with your iPhone 7 or the adapter and another pair of headphones.
I hope that helps.
Have a fantastic day!