Hi @Jonna, Sasanka Welcome to Microsoft Q&A thanks for posting your question.
The error message you provided indicates that the connection to Azure Redis Cache from your on-premises .NET application has failed. There could be several reasons why this is happening, including firewall issues, network connectivity issues, or configuration issues.
You can check the below troubleshooting steps.
I would recommend raising support case if the troubleshooting steps doesn't help.
Regards
Geetha