I used Jekyll 4 on Ubuntu and it worked. Now I cloned the repo to client 2 and use Jekyll 3 portable on windows.
Some of my embedded html now does not get rendered in a markdown file. A <button> will be in page src code: <button> and therefore seen on the page as <button>. Button does not work at all, even without attrs. <div> and <span> work if they do not have attributes.
I use JS all over my site and address it with tag ids and classes. Do you recommend to replace html with markdown? But html is nice combined with md.
(Just avoid inventing HTML in markdown file unless you know what you are doing - bad indentation can cause HTML to become code blocks. )
Jekyll shouldn’t be doing anything to mess with your button to make it escaped as >. Unless you have some tag or layout or plugin messing with things.