DNS nextcloud not accessible

Hello,
Ok then I’m the one who didn’t understand this thing.
However now I have expanded the network for a moment by adding a Tim Modem to my FrtizBox, this was already available previously (the server was connecting to it) but it had as iP: 192.168.2.2, now its new iP has become 192.168.1.2.
The changes compared to before are that it is an Access point that has a web interface (it didn’t have one before), a second Wi-Fi network (it didn’t have it before), and connection to the various LANs.
Now a doubt arises, before my Tim modem worked as a Switch, but wasn’t it he who gave me these problems? If so, how can I solve this problem? just open the ports of this modem plus those of my FritBox?
Kindest regards Nicola Garatti

Hello,
I apologize for my absence, I have had a lot to do with the school, I found that my Intred provider does not provide an external address, because they are suborect with the 10.0.0.0 format.
I discovered this after careful research and the confirmation of my prof by telling me that a client of his had also intred and had this type of manager, the fact is that he too cannot receive an external address and is having problems.
The only one would be to buy an external static IP, but this means that there would be problems related to DDOS attacks (even if I really don’t care and they would be quite rare).
So unfortunately I can’t get a public external IP.
Kindest regards Nicola Garatti.