Custom Lovelace components not accessible via external url when at home, no problem when elsewhere

Since a couple of days, I have the somewhat change situation that - when I am on my own home LAN - I am having trouble to reach my Home Assistant Dashboard via the external url (via wifi). Accessing the same external URL from elsewhere (e.g. on my phone through mobile data connection, not via wifi) works without any problem. Also the internal URL works fine when I am on my home LAN (via wifi again).

After some time, there must be some kind of a timeout and eventually I get the dashboard, however with errors for all the custom Lovelace components that I installed through HACS and that seem to have their files stored in /config/www/community (contrary to the other custom components which are in a folder /config/custom_components.

For the sake of clarity, I’ve attached a screenshot taken while using the internal url and one when using the external url. In case my explanation of the issue was not clear, these pictures will be for sure.

I cannot remember that I have changed anything that could cause this strange behaviour.

Anyone a suggestion as to where to look? Or what could be the cause exactly?

Thanks in advance!!