Yea, it's gotten to the point where you just have to say "YES" to every obvious gatekeeping/filtering question. Whatever it takes to get to the next gate. Out of 10 written job requirements, only 1, maybe 2 are actual dealbreakers. If the job really requires specifically .NET 5, then the technical interviews will grill you on it, and you'd fail for the right reasons.
You'll then get an invite to the technical interview where you can talk to people who actually know whether C+ exists.