Don't use the Edit rows window. It's a little twitchy on a good day 🙂
If you put the trigger back as it was and use an update statement to change a row in the Products table, does the trigger fire and update the datetime?
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability