In Microsoft Skype for Business Server 2019 or Skype for Business Server 2015, if you set the SQL Always On Availability for the Monitoring server, the SCOM SQL alerts are generated every hour on the SQL secondary replica server.
To fix this issue, do the following steps:
Install the July 2019 cumulative update 6.0.9319.559 for Skype for Business Server 2015, Core Components or install the December 2019 cumulative update 7.0.2046.151 for Skype for Business Server 2019, Core Components.
Fail over the database to a secondary database.
Run Install-CsDatabase -Update -SqlServerFqdn <SqlServerFqdn> -Configured Databases.
Run step 3 by failing over the primary database to each secondary database one at a time.