Sorry to hear you’re experiencing some issues here.
While I’m unable to say for certain why this is happening, there are a few things to check and bear in mind.
HTML for email is quite different to the HTML used on webpages. Although it’s the same language email is typically a behind in terms of what it can support. This also ties in to the email client you’re using. What software do you use for email? For example, are you seeing issues in outlook, Gmail, etc?
If you’re stuck, we can certainly take a look to try and advise on issues, although we may not be able to correct them for you. But let me know and I’ll see what we can do for you