Hello DiamondA01,
If your Beats won't stay connected to your iPhone, you'll want to start with these steps:
Check the location
Place your Beats product and your paired device within 30 feet of each other. Move both devices away from other Bluetooth devices, microwaves, wireless routers, and other electronics.
Check the sound settings
On your iOS device, go to Settings > Bluetooth and select your Beats.
Check the volume
1. Make sure that both your Beats product and your Bluetooth device are charged and turned on.
2. Play a track that you downloaded to your device, not streaming audio.
3. Increase the volume on your Beats product and on the paired Bluetooth device.
You'll find those steps listed here: If you can't connect to your wireless Beats product
If the issue persists, try resetting your Beats:
Reset Solo3 Wireless
1. Hold down the volume down button and the power button for 10 seconds.
2. When the Fuel Gauge flashes, release the buttons.
Your headphones are now reset and ready to be set up with your devices again.
More information on resetting your Beats here: Reset your Beats on-ear or over-ear headphones
If you're still having issues with your Beats not connecting to your iPhone, you'll want to check for any sources of wireless interference with these steps: If the sound from your wireless headphones cuts out or is distorted
Take care!