I'm using Visual Studio 2022 with the latest SSIS extension (1.3.2). In my dtsx package I have a connection manager which I don't want to be touched by VS in design time (I'm not manipulating or changing any tasks or components which deal with this connection manager). I thought the property DelayValidation on the connection manager should help, but even after changing it to true I can see a Login attempt being logged in a SQL Server Profiler immediately after I open the package in VS. The only workaround I've found is to activate "Work offline" but then every connection manager is offline (and the setting is per developer and doesn't seem to be persisted) which is not practicable for me. Any suggestions are very appreciated.
*This connection manager is referencing a normal SQL Server database for a case if it matters.
You have identified the only option: "Work offline" but it as you state, that applies to all connections. There is no ability to selectively have one connection offline while the rest remain online.
DelayValidation does not prevent this and every edit to a component/transformation in a data flow is going to cause the Validate (name approximate) method to fire at which point SSIS has delayed validation as long as possible.