The webhook is not reaching our plugin. So something somewhere is blocking that hook so our plugin is not getting any data from Stripe (after a transaction).
Please ask you hosting if they know anything about this (or have seem something similar on any other sites on their hosting). Also, do you have any blocks in your .htaccess file? Sometimes a firewall plugin will put rules there to block incoming requests.
The log file should be updating instantly. If it is not updating instantly, then there is caching happening (you are seeing a cached version of the log file).