Remote Access to HA via VPN and Hue Lamp Issue with Alexa

Hello everyone,

I set up Home Assistant (HA) yesterday, and everything is working fine so far. Now I wanted to set up remote access through my Fritzbox using a VPN. The VPN connection to the Fritzbox works, and I can ping HA, but I don’t have access to the HA web interface.
As far as I know, I have activated the necessary ports, but maybe I made a mistake or missed something.
Does anyone have any ideas on what could be causing this or what else I should check?

Additionally, I have another issue: one of my Hue lamps suddenly can no longer be controlled via Alexa, but it only affects this one lamp. All other devices work perfectly.
Has anyone experienced a similar problem or have any ideas on how to fix this?

Thanks in advance for your help!

Best regards,