Internet disconnects, wifi still connected but won't send audio to AirPlay Speakers

Question

This is getting really frustrating. No one has any solutions, there was a UNIX command one that claimed to work for a lot of people, but it ruined my POS software and had to revert back.
Disconnects from everything connected to the router, but every single other device works fine.  This problem only occurs with my iMac, just like all of the other threads around the internet.

Answer 1

Some users with various Wi-Fi connection problems have reported that they were given the following instructions by Apple Support, sometimes with success. I can't vouch for this procedure myself. After completing the procedure, you'll have to recreate all your settings in the Network preference pane. Make sure you know how to do that before you begin. Taking screenshots of the preference pane may be helpful.
Step 1
Back up all data.
Triple-click the line below on this page to select it:
/Library/Preferences/SystemConfiguration
Right-click or control-click the highlighted line and select
Services ▹ Reveal
from the contextual menu.* A folder should open with an item named "SystemConfiguration" selected. Move the selected item to the Trash. You may be prompted for your administrator password.
*If you don't see the contextual menu item, copy the selected text to the Clipboard (command-C). In the Finder, select
Go ▹ Go to Folder...
from the menu bar, paste into the box that opens (command-V). You won't see what you pasted because a line break is included. Press return.
Step 2
Reset the System Management Controller