Firstly, this forum is for issues with this particular website - not in-game bugs, so if you can, you may want to edit your original post and move it to the Bug Forum or Tech Support where it deals with in-game issues.
To respond to your issue though, I saw someone else with a similar issue, but there was just an extended delay for some reason. The gold showed up an hour later in their mailbox.
Now, if it still doesn’t show up, you may just need to do a full UI reset - not a reload, but a full on reset. You just follow the steps here: