Hi Tsjude,
Welcome to the Apple Community.
If your phone isn’t working right, try re-starting it:
Turn iPhone on or off – Apple Support
and
What to do: If you can't connect a Bluetooth accessory to your iPhone, iPad, or iPod touch - Apple Support
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Re: Beats
You might want to check that you are only connecting earphones to one device at a time
(Eg may not be switching between multiple devices.)
How to: Reset your Beats earphones - Apple Support
Sound troubleshooting – Beats headphones and earphones – Apple Support
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How to: Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support
If needed:
There is a "Get Support" link at the bottom of the iPhone Support Team's website:
iPhone - Official Apple Support
All the best :-)