I use ssh only in local, at home.

I don't want to open a NAT/PAT port on my ISP router bbox... I know i can redirect to a different port but I did not do it before this Christmas weekend.
There is also the fact that before I used a 4G router connected to the mobile network and I connected in wifi on it. But, I do not know if it is the same thing in your respective countries, in France, in mobile network you can not do NAT / PAT because you have a local IP address and not a public IP address. The public IP address is that of the 4G antenna to which you are connected. The ISPs clearly stipulate in their Terms for cexu who take the trouble to read them ....

Of course, i know how to do this NAT/PAT but i think this is not more secure than teamviewer ...