The only hardware change from Ubuntu-3.2.0-19.31 to Ubuntu-3.2.0-20.33 that might have an effect is '(pre-stable) ASPM: Fix pcie devices with non-pcie children'. Can you experiment by adding one of these to your grub boot command to see if it makes a difference ?
The only hardware change from Ubuntu-3.2.0-19.31 to Ubuntu-3.2.0-20.33 that might have an effect is '(pre-stable) ASPM: Fix pcie devices with non-pcie children'. Can you experiment by adding one of these to your grub boot command to see if it makes a difference ?
pcie_aspm=off
pcie_aspm=force