Hi Tuppins440
welcome to the Apple (user-to-user) Community.
Re: "My wireless ear bud on the left side does not work"
Wondering if the volume is too quiet on one ear bud.
Eg: Sound troubleshooting – Beats headphones and earphones – Apple Support
You might want to see if something in this article from Apple Support (link below) can help:
Learn what to do: If your left or right AirPod isn't working - Apple Support
Eg: Go to Settings > Accessibility > Audio/Visual > Balance, and make sure that the balance is set in the middle.
_________________________________________________________
You might want to:
Check the documentation that came with the earbuds, to reset them
or
How to: Reset your Beats Studio Buds - Apple Support
or
How to reset your AirPods and AirPods Pro
________________________________________________________
If you still need help:
Another fix that works in some cases:
Eg: Ear buds may not be switching properly between devices.
"Forget" the ear buds on all devices they have been connected with - Computers, iPads, Phones, TVs.
Turn off those devices.
Then pair the ear buds with the device you mainly use them with.
If needed: You can see what other help is available:
Eg: Beats Studio Buds Support website:
https://www.beatsbydre.com/support/earbuds/studio-buds
or
Contact Apple Support
or
AirPods Support Website:
Find all the topics, resources, and contact options you need for your AirPods....
AirPods Support - Official Apple Support
All the best :-)