Same situation here:
– I installed MD on WP 5.4;
– WP is installed on domain1.com;
– I added domain2.com and domain3.com to MD;
– When I access domain3.com, it simply redirects to domain1.com instead of keeping the domain3.com with the contents of domain1.com.
I’ve tried on the ISP server to have domain2 and domain3 resolving as ALIAS and as ADD-ON domains, but get the same results.
Any clues?