Screen Sharing Failure

I have a “headless” Mac Studio that I use for email filtering, as a file server, and a few other things. Normally, it just sits and runs quietly without me needing to do anything to it. However, when I do need to fix or do something, I’ll remote into it from my MacBook Pro over the local network. I can currently see the Mac Studio and connect to it via the Finder and browse the various drives, however, I can’t for the life of me establish a screen-sharing connection, something that I’ve previously done a million times.

Both computers are running Mac OS 15.0.1, and are connected to the same network–Mac Studio via ethernet and the MacBook Pro over wifi. I’ve rebooted both computers, and on the Mac Studio I’ve disabled Remote Management and Remote Login, and ensured that I have access in Remote Management, but still get no love.

Any other suggestions?

Why not Use Jump Desktop

This is going to sound bizarre, but I’ve had occasional issues with screen sharing that always coincide with system updates being ready to install. It won’t respond to anything, forcibly rebooting doesn’t help. So I manually move a monitor/keyboard over there, see that it has updates, install the updates, and it’s good to go again.