@nhbriggs installing OpenSSL 3 alongside OpenSSL 1 shouldn't have broken anything - that's the default state of Solaris 11.4.42 through 11.4.80 while we worked through converting all the software that used OpenSSL 1 to use 3 instead. But drop-in replacement can't work as they're not compatible (hence the change of major version number) - if you've done something like that, booting from a previous BE is probably your best choice, since the pkg system depends on OpenSSL.