Custom SMS & Phone Message error

In version 7.9 I had created custom SMS and voice notification messages. After upgrading to 8.0 I had to revise ALL of those messages to include the concat( instruction to build the messages using strings and parameters. This was a very tedious proces, but I thought it was completed.

Unfortunately, I was wrong. When I get an actual voice notification, the message is not evaluating the {Timestamp} alarm parameter into hours:minutes:seconds, but rather saying the numerical values. How do I fix this?