Dynamic Link ID not tracking

Hi All

I've got a question about the link id you put on an a tag. Can this be a variable if u use velocity scripting?

My link ID is dynamic, marketo registers the click, but not the link ID.

What I get on a user:

What's in my velocity code:

<a href="https://${brochure1.onlineUrl}" target="_blank" title="Read Online $brochure.name" id="online_${id1}" style="color: #004fa3;">
Read Online
</a>

${id1} is just a number. When previewing the email, it renders correctly.

It renders like id="online_2"

Thx!

Thomas