I have a working website. I want to do some tests with client certificate. When I go to IIS / SSL Settings in IIS Manager, then set Client certificates: Accept, strangely, the website does not prompt for certificate. It displays This site can’t be reached, ERR_CONNECTION_RESET.
It does this with Brave, Edge and Chrome. However, with Internet Explorer, it requests the certificate, then returns a 403.16 error, as if the certificate were not trusted (it looks like another error).
The setting of Accept or Require flips parameters sent to Windows SChannel API that handles TLS connections for IIS. Like you found out, not every web browser vendor is compliant to that Accept mode (except Microsoft's own IE).
It's more common to use Require.
Require SSL without any better result. I also tried the option Require. On another server configured by someone else, I have the comportment I want. When connecting with Brave, it asks me to provide a certificate. So I'm confused on how to configure it to accept or require client certificates.