Hi!
Thank you very much for your kind words!
Error 403 usually indicates when there is a resource forbidden on the server. In this case it is namely the ajax handler, which should return the results.
If the cases are isolated, then the most likely cause is either:
– Firewall or any other restriction. There might be a rate limit in effect, that may trigger a firewall at the server, which then forbids the access to the given file. Usually it’s either by IP or by user agent.
– Temporary server outage/maintenance at that time
– The connection on that specific device has some sort of issues
Based on your description I would suspect a firewall. It could be sucuri or something else. Try deactivating all of the security measures on the server side, to see how it changes.