RaspberryPi cannot be accessed by TeamViewer from 'outside' network

Hi Guys,

Over the last 2years, I've installed TV on many Raspberries and could access them from networks outside of my office, please have a look at my issue:

I can access 2 RPIs in my office normally.

I have added 5 new RPIs in my office to Teamviewer that show up as online in the console but I cannot access them from a remote network. I could access each of the 5 newly added ones in the office network. All of these RPIs are clones but I did sudo apt purge teamviewer-host on the first installation so each one has its own teamviewer-ID. The only thing that I did differently was installing hostapd:

But I have already reversed that by:

sudo systemctl disable hostapd


sudo nano /etc/dhcpcd.conf and comment these lines:

interface wlan0
    static ip_address=
    nohook wpa_supplicant

The RPI could connect to the local WiFI without any issues again and was connected to the internet.

My intuition tells me the problem could be related to the hostapd installation but I don't know how to troubleshoot it from here.

Thank you!