Trying to Taildrop a file from a macOS machine to a linux machine, the macOS Taildrop UI shows the progress indicator filling up all the way, then it hangs for a bit, and then fails with an exclamation mark icon. A macOS notification then pops up:
Failed to share with Linux Machine. Reconnect Linux Machine to Tailscale and try again.
The linux machine is definitely connected & otherwise working well with Tailscale, so this message seems to be not quite right.