I've created the following add_meta_box and associated fields but the problem I'm having is that the content of the meta box fields disappears after about 10 minutes. I've tried vairious solutions online but none seem to work. Any help or tips apprecated.
I've also been told elsewhere not to use admin_init however renaming the function causes the meta box to disappear from inside the CMS, any futher advice on this would be greatly appreciated.
[Code moderated as per the Forum Rules. Please use the pastebin]