How can I fix "Pairing Unsuccessful" error messages on my iPhone 12?

My MacBook Pro and iPhone 12 are no longer paired in Bluetooth, though both are up to date. On my iPhone, I get two "Pairing Unsuccessful" error messages: "Pairing took too long. Make sure MacBook Pro is turned on, in range, and is ready to pair." It was turned on and right next to my iPhone, which was connected to it. I tried again after connecting my MacBook to power, but it still did not fix the problem. The other error message read: "MacBook Pro is not supported."

Other information regarding this problem is that my MacBook was not listed with my devices in Bluetooth on my iPhone. Instead, it was listed under "Other Devices" and now it is not coming up at all. I have checked Bluetooth on my MacBook. It is on and says that it is discoverable. Also, my iPhone 12 is not coming up with my devices in Bluetooth on my MacBook, just my AirPods are. I am signed into AppleID and iCloud with the same username and connected to the same wifi, and again, both are up to date. How do I fix this?

[Re-Titled by Moderator]