Edit: Looks like it does work in Play Solo. Maybe there was a bug that caused it to yield indefinitely a couple minutes ago?
Apparently “Enable Studio Access to API Services” only applies in Edit mode. Once you hop into Play Solo, DataStore calls yield indefinitely. This means we have to use Play mode to test, defeating the purpose of Play Solo. DataStores should work in Play Solo in addition to Edit mode if “Enable Studio Access to API Services” is checked.
Yep – I was editing a group place published to the site. On second thought, it started working once I reopened studio after it crashed. The place had been open for several days so maybe that had something to do with it.