I ran into the same problem with OpenSSL 3 and Windows Server 2012 R2. However, I eventually put together the correct combination of parameters. This seems to work:
openssl pkcs12 -export -certpbe PBE-SHA1-3DES -keypbe PBE-SHA1-3DES -nomac -inkey contoso.com.key -in contoso.com.crt -out contoso.com-legacy.pfx