Remote access

[carlospj]

From the info you provided, your port forwarding and Cloudflare setup are correctly.  The only thing that would prevent it from working is if your ISP uses CGNAT (carrier grade NAT).  Similar to how consume level NAT works, 1 public IP for multiple devices, some ISPs do the same at the ISP level.  CGNAT pretty much makes it impossible to host a service since your IP changes pretty frequently and the carrier blocks unsolicited incoming requests like your router would if you don't setup port forwarding.

If you go to https://whatismyipaddress.com/ again and if the IP is different than yesterday, that is a pretty good indicator that your USP uses CGNAT.

I hope that's not it, but nothing else seems to make sense right now.
That said, the IP hasn't changed and is still the same as it was yesterday and almost certainly the same as when I opened the post, two or three days ago. I'd even want to swear that the number rings a bell enough to say it hasn't changed in a while.

In LAN Options, can you show me "IP Alias"?

Yeah, sure. Here it goes:
   

These are the options:
   

And this is what IP Alias row has:
   

The other two options had IP addresses that I don't know if I should share. They are disable anyway.

Or you can provide me with your router model and maybe I can find a manual for that model.

The router is Smart Wifi (HGU) GPT-2741GNAC

One more thing I just remembered. When I did the installation of the Ethernet cables when I did the works in my house, all the cables converged in the living room, in a kind of “box” that was inside the wall.
Originally the idea was to put the router in there, but, one, it was too big, and two, it got too hot, and I didn't want to leave that in there as a precaution.
So I bought a switch (I think it was a switch, because it's a long time ago and I don't remember it very well), where I connected all the Ethernet cables in my house, and then one from the switch directly to the router.
Could this have something to do with it?