Analyze and diagnose failure of Arch Linux getty terminal to receive keyboard input

I have an important Arch Linux system which since the January 2023 upgrades has developed some problem that is preventing the initial getty terminal used by the virtual console to receive keyboard input. This prevents the machine from being logged into locally. Otherwise the machine behaves correctly and can be operated remotely via SSH. There are no error messages and it is certain that keyboard events are occurring (eg evtest shows the events happening). getty is just not processing the events for some reason.

I am looking for someone to investigate why the virtual console is not accepting keyboard input and determine the exact cause.

The developer should be expert in Linux system development and be capable of doing kernel level debugging.