@dmalygin 

Hi,

Your router's current IP address of 100.77.147.145 falls within the range that has been assigned for ISPs to use for CG-NAT.

https://en.wikipedia.org/wiki/Carrier-grade_NAT

These reserved IP addresses cannot be reached from the Internet.

185.16.138.73 is a public IP address that your ISP shares between their customers.

If you were able to access your home network from abroad previously, then your ISP must have recently switched your broadband connection from being assigned a public IP address to a CG-NAT IP address.

I am surprised they did that without notifying you.

  @woozle Yes indeed, no notification at all, my surprise is not less than yours :)

Thank you very much for your help, appreciate a lot

  @dmalygin You can see if your ISP has IPv6 support. If yes, you can access your PC from the internet.

Use this page to test:

Test your IPv6