Hi – The inventory is synched on the hour by spawning a cron job.
Things to check:
1. Are cron jobs disabled on your site which is often done as a DDOS attack precaution?
2. Are the comms working between Woo and Xero? Are you creating invoices ok?
3. What is the message in the debug screen?
4. Do you have any other Xero or stock control plugins on your site?
5. Set up a test product in both Woo and Xero and test it both for the shop which synchs just that product and for the global inventory synch.
6. Is your inventory going below zero?
7. Does inventory in Xero synch with Woo as the master?