Black wire(s) from the fixture to the single black wire from the ceiling box. White wire(s) from the fixture to the bunch of whites from the ceiling box. Leave the bunch of blacks with one white as it is and tuck it back inside the box.

Thank you @w0lley32!

I tested the wire bundles with a contactless voltage tester today. Here are the results:

• Nut 1 (black - 3 black wires, 1 white wire): high reading, regardless of whether switch is off
• Nut 2 (red - 3 white wires): zero reading, regardless of whether switch is off
• Nut 3 (red - 1 black wire): high reading when switch is in on position; low reading/beeping when switch is in off position

Does that information confirm or modify anything you suggested above?

Great thanks @w0lley32! I'm getting the fixture in a few days and will let you know how it goes after I set it up.

@w0lley32 belated confirmation that your instructions worked perfectly. Thank you!

You're welcome! Enjoy your new fixture!

Just want to say thank you @w0lley32. I had this same situation and the same question of what to do with all the wires coming out of the junction box. I followed your instructions and now the fixture is connected to the switch again and everything works normally