Catalina can't find Sierra on AirDrop

Hello and welcome to Apple Support Communities, DWtsn!

I understand you're not able to see your MacBook Pro running macOS Sierra from your MacBook Pro running macOS Catalina. I'd be happy to provide information to help you troubleshoot this.

Give the following steps a try: Use AirDrop on your Mac

"If you can't see the other device in AirDrop

If a device doesn't appear as an AirDrop recipient, make sure that both devices have Wi-Fi and Bluetooth turned on and are within 30 feet (9 meters) of each other. If that doesn't help, check these settings on your Mac or iOS device.

On Mac:

• Choose Go > AirDrop from the menu bar in the Finder, then make sure that AirDrop is turned on.
• Check the ”Allow me to be discovered by” setting at the bottom of the AirDrop window. When AirDrop is set to receive content from Contacts Only, both devices must be signed in to iCloud, and the email address or phone number associated with the sender's Apple ID must be in the Contacts app of your Mac.
• If the Mac is from 2012 or earlier, click “Don't see who you're looking for?” in the AirDrop window or sharing sheet of the sharing Mac. Then click “Search for an Older Mac.”
• If the receiving Mac is using OS X Mavericks or earlier, make sure that an AirDrop window is open on that Mac: choose Go > AirDrop from the menu bar in the Finder. 
• Make sure that “Block all incoming connections” is turned off in Security & Privacy preferences of the receiving Mac.

On iPhone, iPad, or iPod touch:

• Check the AirDrop setting in Control Center. When AirDrop is set to receive content from Contacts Only, both devices must be signed in to iCloud, and the email address or phone number associated with the sender's Apple ID must be in the Contacts app of your iOS device.
• Make sure that Personal Hotspot is turned off in Settings > Cellular of the receiving iOS device."

Have a great day!

Hello,

Did you find a solution to your problem? I’m asking because that auto response you received is misleading/incorrect. The problem is that under Catalina, Apple has removed the feature in AirDrop where it used to give the option to click, “Don’t see who you’re looking for?” And then select “Search for an older Mac.”

I have a classroom lab of varying models of Macs and this issue has plagued me since updating to Catalina.

I have exactly the same problem as you!