Mod is installed on both host and guest. No machines are pulling from or to the chests inside a shed.

Running "automate summary" on the SMAPI console does not show the machine groups in the shed, but using the overlay on both host and guest in the shed shows the machine groups marked in green.

Nevermind, I guess the location was not dynamically added to the list of locations to automate when it was constructed during the session. Restarting the game sorted the issue.

Hi! That's a known issue with SMAPI events; see Pathoschild/SMAPI#710 for more info.