How to forward ports on a 3G / 4G router in the Megafon network with a static IP?

Question

Computer networks

I can’t forward ports on the 3G / 4G Huawei B525 router in the Megafon network with a static IP. The magic is that when creating rules for virtual ports in the router menu, they (ports) are visible open from the global web (I used the ip2.ru site). In addition, when accessing a static WAN IP through port 443 (i.e. via the https protocol), the web interface of the router opens (for some reason it does not work via http via port 80). However, I cannot access local network resources from the Internet through these open ports: see, for example, the Apache2 "It works" welcome page, access the DVR, etc. The browser says that the server was not found. Tried disabling the firewall and playing with DMZ - nothing helps.
I thought that the problem was in the Huawei router, I changed it to TP-Link Archer MR200. The result is almost the same, with the difference that now there is not even access to the page with the router's web interface.

The trace seems to point to a double (more precisely, even triple) NAT provider:
[email protected]:~$ traceroute 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 64 hops max
1 192.168.8.1 1,038ms 0,815ms 0,917 ms
2 193.201.229.208 513,063ms 50,124ms 49,693ms
3 10.77.245.13 51,787ms 49,843ms 49,950ms
4 37.29.105.81 383,007ms 126,413ms 76,811ms
5 178.176.152.61 167,516ms 157,250ms 54,604ms
6 108.170.250.99 55,758ms 47,911ms 51,968 ms
....
But Megafon says that everything is okay on their part. And indeed, the ports are visible open and the web interface page of the router is loaded. I don't understand anything.
Explain, good people, what's the matter? what am I doing wrong? I hope this question is "simple" )
PS Linux Mint is installed on the machines

Answer 1

There is such a problem with a megaphone - to close the ports.
There was a case. They sent a link to ftp so that you can download the materials. When you try to log in to ftp (port 21) via a megaphone from any device (smartphone, PC via huawei modem), nothing happens. From the phone Tele2, Beeline - enters ftp without any problems. At home, already through WIFI with the same settings as on a megaphone, I calmly entered FTP.