Steps to reproduce:

1. Edit any trigger located at: Configuration -> Templates -> MSSQL by ODBC -> Discovery rules -> Database Discovery -> Trigger prototypes
2. Navigate to a host already holding the template and re-run the discovery rules or wait for 1h (Default: update interval of the template)

Result:

1. The template won't update, only re-attach the template will re-create the correct triggers (loosing all history). 

Expected:

1. The template gets updated, without the need for re-attach

Image:

1. This is the host already holding the "old"-trigger (default eval period was 5m)
2. Shows where that I updated the template (both name & expression) to use {$MSSQL.LOG_FLUSH_WAIT_TIME.EVAL_PERIOD:" {#DBNAME}

   "} as eval period.

1. 1. I am not sure if the avg expression can hold such a macro, but not relevant as I also had the issue a few days ago when changing the min function (=default template trigger) to avg.