With Java 17 gaining more acceptance, one thing it doesn't support anymore are older Java web apps used on networking switches and KVM devices. You'll need to work around it, to gain access to those systems. This other post I found was helpful, though it's for a Linux context.
# See "jdk.certpath.disabledAlgorithms" for syntax descriptions.
# jdk.jar.disabledAlgorithms=MD2, MD5, RSA keySize < 1024, \
# DSA keySize < 1024, include jdk.disabled.namedCurves
jdk.jar.disabledAlgorithms=MD2, RSA keySize < 10244. You might have to do the same for the jre/lib/security/java.security file where you installed OpenWebStart.
5. Try opening the JNLP file.