This behaviour seems pretty consistent, but I cannot find any documentation from google (or anyone else) that would say that this is the case, and what are ways to deal with this issue.
Is it possible to use redirection/url-shorteners with eddystone-url?
There are a lot of ways in which triggering might not work including no connectivity, not using SSL and slow shortener. Here's a comprehensive troubleshooting guide.
Url shorteners are almost always used with Eddystone-URL, and I have commonly used them with success. So I suspect something else may be the issue.
If using Nearby or Chrome to do the detection, you must make sure that the URL can actually be resolved to a website, and that there is not robots.txt in the root of the site that prevents crawling the pages. Google needs to crawl the pages to give a title and summary of the page associated with the URL.
after some trial and error...
Found out the requirement I was missing was that the links I was using did not have meta tags.
I was able to use my https re-director to forward to the google website. Then I changed the redirection to a different link, but that no longer works, it only forwards to google. I've removed all links, so there's no way it could redirect at all now, but chrome-pw and the physical-web app still shows the google website.
Some time later, I set another url and it worked again, but a subsequent change would not be reflected.
It looks like google knows that it's using a redirection service and resolves the link. It also caches it, so subsequent changes do not go through.