I created some custom styling for a woo commerce calendar ui. I cloned my website which contained that custom styling into a subsite of a multisite network. This is a subdirectory network, not subdomain. On my subsite the custom styling isn’t visible when I’m not logged in. When I login as an admin on the website, then the custom styling shows up when I’m on the page. I thought this was a caching issue to I disabled all caching plugins and disabled page and object caching on my host server. Even with all caching disabled and all caches cleared, the custom styling does not show up on my site unles i’m signed in as an admin.
There is a Publish button at the top right of Microthemer. Can you try publishing your settings when logged into the subsite? If that doesn’t help, the troubleshooting video lists some other reasons why styles might not show to non-logged in users.
Failing that, I would be happy to troubleshoot this if you can send me temporary access details to the site via our secure contact form. You can use this handy plugin to provide temporary access easily.
P.S. you may need to clear your cache after publishing too.