Sync not working? (Multisite?)

Hello,

We have been using this plugin for a while without any issue. Recently we updated WordPress as well as some plugins which were significantly out of date. Somewhere along the line the plugin has seemingly stopped syncing for any child site on our multisite network (whether it is activated on its own or network activated). We have different API keys for each subsite, and this has worked in the past — but I’m a bit lost as to why it’s working fine on the parent site and only the children seem effected (same theme, same settings, etc)

The sync button itself is disabled and says that the process queue is running all the time (when it’s clearly not). Even removing the disabled flag so I can click the button does nothing (although it gives a notification that the sync has started, but nothing else).

I see no console errors or anything either.