Cannot restart Product Sync

We recently (13 Feb) temporarily turned off product sync, however on restoring ‘Enable product auto-sync’ there have not been any logs generated and we are seeing differences in price from the rules in the Product Price tab.

Have de-activated and re-activated the plugin, also changed the sync time, all to no avail.

FYI –
Use HTTP service URL – ON
Exclude on-sale products – OFF (all Ali products are set to be on sale)

Do you know what may be happening here? Can you advise on how to restore Product Sync?

Thanks