As history tests, I am no reg-ex expert, but I've figured out a few monkey see monkey do style, but I'm a bit flummoxed with Odysee embeds.
This is the regex I'm using and that seems to work 
Odysee Embeds
Watch:
(?:<a.*?)?(?:https?:\/\/)?(?:www\.)?odysee\.com\/@([a-zA-Z0-9_-]{1,64})([a-zA-Z0-9_-]{1,64}):([a-zA-Z0-9_-]{1,64})(?:.*?\/a>)?\/([a-zA-Z0-9_-]{1,64})([a-zA-Z0-9_-]{1,64}):([a-zA-Z0-9_-]{1,64})(?:.*?\/a>)?
Therefore I believe it's the embed that's floundering. The below is not doing the do - anyone?
Replace:
<div class='embed-wrapper'><div class='embed-container'><iframe id="odysee-iframe" width="560" height="315" src="https://odysee.com/@$1$2:$3/$4$5:$6" allowfullscreen></iframe></div></div>
... help! 