Please disregard.

I extracted DTB/DTS from the Android FW (files attached). For whatever reason they are signed in the image as rk3568. No ideas why. 02_dtbdump_rockchip,rk3568-evb.dtb 02_dtbdump_rockchip,rk3568-evb.dtb.dts

I have compiled debian trixie image from the repository of @johlnx for Vontar DQ08 4G+64G and flashed it to eMMC, also adjusting the DTB for wifi GPIOs. Wifi works with the brcm4335 firmware (at least in the 2.4GHz band), usb3.0 works too. Bluetooth does not work and there are still many nasty error messages in the 'dmesg' output.

Proprietary DDR and maskrom images from Rockchip Bare metall should provide DDR init replacement code, the only missing part in u-boot.

I assume you are talking about local connection here, not from the internet, so it's ngiinx webserver you are talking about, not nginx-reverse-proxy? Can you at least ping the ip of the server? Syncing apps might not connect over http or https (or rather, they probably don't), which your browser does. Are you sure letsencrypt works properly and it's not just your browsers refusing to connect over https due to missing/miss-configured ssl certificates? Does forcing http connection at least give you some response? As for using wget to test: "wget --spider <url>" should get you some info. It should look something like this for correct setup using https: (enter url without http or https, I have redacted url and ip for obvious privacy reasons) $ wget --spider <your_url_here> Prepended http:// to '<redacted>' URL transformed to HTTPS due to an HSTS policy Spider mode enabled. Check if remote file exists. --2026-05-23 14:48:27-- https://<redacted> Loaded CA certificate '/etc/ssl/certs/ca-certificates.crt' Resolving <redacted> (<redacted>)... xxx.xxx.xxx.xxx Connecting to <redacted> (<redacted>)|xxx.xxx.xxx.xxx|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 0 Remote file exists and could contain further links, but recursion is disabled -- not retrieving. But as eselarm said above, we need way more information to be able to help.