Neither Ethernet nor WiFi adapter working on Lenovo Thinkpad P14s under Ubuntu 2x.04

After days of research on the web and trying different potential solutions, I have finally found the solution. It's plain and simple:

sudo apt install linux-oem-20.04d

As an issue in a github repository working on drivers indicates (https://github.com/lwfinger/rtw89/issues/75), the OEM variant of Ubuntu 20.04 does contain the drivers already. I tried it, and it worked like a charm.

Note: Before doing so, I phoned Lenovo Premier Support, who told me that the issue is exactly with GEN 2 variants of the Lenovo Thinkpad P14s, as this notebook is not officially supporting Ubuntu, whereas for the Gen 1 variant the Ubuntu community had already included approved drivers.