iOS 10.0.1 Bug: ask to join wifi networks pops up when receiving a call

Hi there, Shannon Phillips.
Thanks for using Apple Support Communities. I see you're invited to join a network even after it's turned off after upgrading your iPhone to iOS 10. Let's get that working like it should then.
1. Check the App Store on your iPhone to be sure you've updated everything. Amazon Music with Prime Music shows a new update as of September 12, 2016.
2. Restart your iPhone, iPad, or iPod touch -- Never underestimate the power of a good restart.
3. How to back up your iPhone, iPad, and iPod touch -- The next troubleshooting step should only reset your iPhone's settings to default, but it's always better to "have" a backup than to "need" a backup.
4. Reset iPhone settings -- Go to Settings > General > Reset > Reset All Settings. Re-select the settings you had previously to see if this has fixed the problem.
If you didn't back up your phone at step 3 but the issue persists, the next step will erase everything on your phone to allow you to install a fresh copy. Please make sure your personal information is safe.
5. Use iTunes on your Mac or PC to restore your iPhone, iPad, or iPod to factory settings -- You'll need to use iTunes on a computer as using the settings on your phone will only remove your personal information.
The first time through select "Set up as a new iPhone" and log into your iTunes & App Store and iCloud accounts. Download and sync the information you need. Test the issue regarding "Ask to Join Networks". If the issue is resolved, continue on.
6. Restore your iPhone, iPad, or iPod touch from a backup -- This article will guide you through the process of replacing your personal information back to your iPhone.

Have a great day!