It's worth noting that unfortunately some code isn't whitelisted on Toyhouse, but is on Circlejourney. There's also some code that is rendered incorrectly by Toyhouse and needs to be rearranged a specific way to work correctly. This mostly applies to CSS, but I've seen this occur with HTML such as <a> tags around <div>s as an example. SVGs also aren't fully supported by Toyhouse right now.
I've been trying to code a toyhouse page using circle journey and it's working fine there, but when I try to put it back into the character's page parts of it vanish for some reason. (WYSIWYG is disabled) My friend is also having this problem.
BreezeFeather I am only now realising that Toyhouse doesn't give me notifications of new forum posts :( I'm sorry for the late reply! So like Mercer said, some HTML and CSS properties are blacklisted on the Toyhouse website specifically, and I don't really have access to TH's blacklist so I can't really reliably implement the blacklisting. Maybe in the future I'll talk to cyan about blacklist stuff, in the meantime you'll have to double check the code on TH every once in a while to make sure it's working as intended!