Hi siena2516
Welcome to the Apple Community
Re: "One side of Beats Solo 3 wireless not working"
Resetting was a good step to try.
Wondering if your Beats firmware is updating automatically.
About Beats Updater – Apple Support
You might want to see if anything in this article from Apple Support can help:
If your headphones don't work with your iPhone, iPad, or iPod touch - Apple Support
Eg: says:
If you can't hear any sound or if only one side of your headphones works
✽. Adjust the volume with the volume buttons on your iOS device or use the Volume slider in Control Center on your iPhone or iPad.
✽. To see if you need a replacement, try a second pair of headphones. If the second pair works, contact the manufacturer of the initial pair and ask if you need a replacement. If the second pair doesn't work, contact Apple Support.
All the best :-)