TP-link DDNS saved as trusted domain, yet offline (answers in EN/DE/FR/LU appreciated)

Hi all,

I created my account on this forum specifically for this issue as it’s driving me insane.

Background information: I’m an absolute rookie and follow Youtube tutorials and forum posts, so apologies in advance if the resonance from my side appears underwhelming (I’m giving my best shot).

So during these isolanionist times I’m trying to set up a NAS/cloud and stumbled across Nextcloud - so I got myself a Raspberry Pi 4B (2 GB) and flashed an SD card with NextCloudPi. Fortunately, the initialisation is mockingly easy. Locally, everything works as intended; but I wanted more, I wanted to be able to access it from outside my wifi range. I folllowed these instructions (/watch?v=g1mYxrxdJXM), but used the DDNS service that came alongside my TP-Link Archer C6 v2.0 Router (xxx.tplinkdns.com). It bound automatically to my router and I added it to the array of trusted_domains and… nothing.

As I mentioned earlier, when I’m reading posts about similar problems, I’m silently nodding and trying to apply it to my case, so I’m not entirely sure what information you, the reader, would need to assess the situation properly, so feel free to ask away and I’ll try to comply.

One detail that might be wort mentioning is that my ISP (T-Mobile NL) provided me with a Modem-Router (Huawei HG659) but I’m using it with the TP-link Archer C6. Can this elicit the observed issue?

No matter if you can or cannot help, I want to thank you in advance for reading this far.

Best,
Zap