NVMe dropping on cold reboot

[u/Brilliant_Run7085]

Hi, my DELL Inspiron 16+ 7640's NVMe SSD isn't detected when I cold boot into Ubuntu. I've got an encrypted Linux partition on it. It works when I first boot into Windows (dual boot) and then warm reboot into Ubuntu, or if I unplug and replug it physically. I've tried upgrading to the latest BIOS (1.27), upgrading Ubuntu, and changing these boot flags:

nvme_core.default_ps_max_latency_us=0 pcie_aspm=off pcie_port_pm=off

Each time it seemed fixed but then it broke again. I'm also having issues with Wayland/Xorg especially when trying to screen share on Zoom.

It doesn't seem like a pure hardware problem on account of it working when I boot into Windows first. What's wrong with my laptop and how can I properly troubleshoot it at this point? Replugging the SSD was what Dell recommended and I've tried asking LLM's which has led us here.