Bluetooth audio distortion iPhone 7 plus

As of 9/8/18 these are the statuses of my devices:

iPhone 7 Plus 128GB running 11.4.1

2015 Retina MacBook Pro 13 inch running High Sierra version 10.13.6

iTunes version 12.8.0.150

*Note: All the music I own is downloaded directly to my MacBook and iPhone*

Here's my problem:

I recently bought a pair of bluetooth headphones, the Sony MDR XB950N1. When I connect the headphones to my Mac and listen to music downloaded on my computer it sounds amazing no matter what song or what level of bass or treble or volume. When I pair the headphones to my iPhone, the majority of my music also sounds just as clean and crisp. However, there are a few songs seemingly at random that sound distorted and scratchy and just terrible. There's no rhyme or reason to which songs sound poor. Some songs off of an album sound great while others on the same album sound terrible. There is no pattern to artist, genre, source or anything else I can think of.

I checked when using the headphones on my Mac and the codec used is aptX. I am aware that the iPhone does not support aptX but rather Apple's own AAC. I have read numerous pieces about the quality of AAC being both equal to and lesser than aptX. The problem seems to happen only during parts of the song where the bass is more prominent. I have used the headphones on two other MacBooks listening to songs that sound distorted on my iPhone and they play fine on the Macs but still play distorted when listening to the same songs using a friend's iPhone 8 Plus 64GB.

Here's the weird part: I tried playing a few songs that sound distorted on my iPhone through the iTunes store instead of locally from my device and they sound perfect. So I went out on a limb and purchased those songs from the iTunes store and synced them to my devices only for them to still sound distorted on my iPhone when I play them but not on my Mac.

If anyone has any possible reasoning and/or solution for this, it would be greatly appreciated. The Sony headphones are amazing in my opinion and it's very frustrating that I cannot enjoy them equally across all of my Apple devices.

Thank you!