Hello
I have a DIR-850L A1, 1.21WW (Europe). Behind the router I have a Raspberry Pi to which I want to connect through SSH on port 443.
However, the router makes this impossible. Any port I try to forward from my Raspberry Pi does not get through the router.

I have forwarded ports for my NAS and Pi. My NAS I can access from outside my network but the Pi I cannot.
However. The Pi gets an IP through DHCP reservation, and if I change the IP to a different one, the port is forwarded for a couple of hours.
After those hours the port is never able to be accessed again. When trying to use a completely static IP, the port forwarding does not work at all.
Is there any solution for this? I would prefer to keep using this router as it has served me quite well.
Thank you