Having Weird SQL Connection Issue for named instance

SQL Server Administration
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After SQL Installation for SQL 2019 and Cumulative Update 19, we are getting below error

provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified

I can connect in SQL Management Studio with InstanceName,port in local machine. I do have to include port in local machine. SQL Browser is enabled and TCP/IP and named pipes are enables.

All SQL ports and UDP 1434 is also allowed in Mcafee. Wierd behaviour. SQL Agent starts and then stops with above error and SQL Error Logs also doesn't open and we get same above error.

Anyone faced before and how to resolve it. Thanks

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We use Mcafee and not Windows defender so I think it doesn't help