Hello,
Thank you for providing more information on this. I think I know what’s going on now.
You mentioned that the cron job is stalling, but the moment you shut down the wallet on your VPS, then the cron job finishes. This is a clear sign that the communication to the wallet is stalling and running into a timeout. I am guessing that the cron job is stalling for about 30 seconds, since this is usually the default PHP timeout value.
Please check again that you can connect to the wallet on your VPS from your WordPress machine. If you ran that PHP code you found on another machine, this is not helpful as a test. The wallet checks the incoming IP.
Remember, firewalls can be either on the VPS side, or on the side on the WordPress server. It would be best to talk to each of your hosts. Explain to them that you need TCP communication on the port you are using for the wallet RPC, outgoing from the WordPress server, and incoming to the VPS.
Additionally, check the rpcallowip setting in your wallet’s .conf file. https://en.bitcoin.it/wiki/Running_Bitcoin Check that you’re using correct CIDR notation to specify the netmask. See here: https://bitcoin.stackexchange.com/a/32268/8738
with regards