Home Assistant iframe isn't working properly?

I’m trying to add a bus schedule to the dashboard.

My city offers very good tools for monitoring busses. Let’s take a random bus stop:

Those are the two available tracking sites for this bus stop.

Here is my attempt to add them to the dashboard:

If I add the first site, it shows in the iframe correctly but the second, better option, just shows white iframe? Why is this?

Could it be related to “X-Frame issue” ?
I needed to install some plugin to Chrome to make my iframes working.

Why not use an integration and get the data into HA, so you can do automations and notifications on it.

I have just opened the Lissu timetable-frame to a new tab (like this https://lissu.tampere.fi/timetable/monitor/index.html#?stop=1694 ) and then added that url to my Home Assistant.

Didn’t know about the integration then, maybe I will try that one day.