Does anybody have any suspicion about what service it is?

I have not used it for streaming, but you’re right. I purposely do not proxy my media traffic for this reason, utilizing their other solutions.

It’s a free service, I think that’s fair.

There’s always other free options like duckdns, etc.

Everything I see online says it’s free.

I’ve also used it recently and did not pay for it.

You can use Cloudflare Tunnel as well.