If I go to SYSTEM > NOTIFICATIONS > INBOX and click the "REMOVE" link next to any of the active messages, the page refreshes and the message no longer appears in the listing indicating it has been successfully permanently "REMOVED".
The next day the message reappears as if it had never been removed. Is that normal behavior or should a massage PERMANENTLY be removed when clicking "remove"?
I also attempted to select all 248 messages in my admin inbox and remove them all. They appeared to be removed and the inbox showed that there were zero messages left in it (see image)
The next day all 248 messages will reappear in the inbox like they were never removed.
How can this problem be corrected so when I remove all of the messages in my inbox, they stay permanently removed and never reappear.
This happens every single time I try and delete any of the messages in the inbox.
It has been three days now and the messages remain deleted thanks to Jonathan's insight into the problem. It was in fact the cache maintenance script that I was running every night via cron. It would reset the red/deleted flag and the messages would all reappear as though they were never removed or read.