Good evening Simon and welcome back!
Thank you for reaching out to us.
I would love to help you with this topic.
What is going on is that in the list view, the excerpt section is not accepting HTML by default.
The good news is that you can totally change that using the following: https://git.io/vrcXG
You can control what gets displayed by using the except field in the Edit event screen.
The snippet above will let you put in HTML tags (such as )
Let me know how that goes.
Best regards,
Geoff B.