Try just with one paragraph:
With SmartLink DU you can insert up to 5 URLs to a single link. Every
time the page is loaded, one of the 5 URLs you’ve entered will be
inserted in the link randomly.
The only “weird” thing that I saw was that you have multiple paragraphs and they were all together, if you put only one paragraph and it works you can try to add a line break between them.
It’s a pretty buggy think, you could report it on: [email protected]