The suggestion to uninstall the "Standard PS/2 keyboard" driver via the Device Manager (Right click "This PC" in File Explorer\Manage\Device Management\Keyboards), and then restart solved the issue completely. Restarting the system will reinstall the same Standard PS/2 keyboard driver. The fix did not involve any download from drivereasy.com. The correct driver is already on the system apparently.
Here is the rest of the story...
This is just amazing. Last night our Acer Swift failed to take input from the a, n, x, c, f keys. The rest of the keys worked fine.
A wireless external keyboard worked fine with all keys. The onscreen keyboard worked fine. We called Acer Tech support. The suggested
troubleshooting was to complete a system restore using the left shift key and restart under the Start button. We completed the both restores 1st keeping files and 2nd removing all files. This was only solution offered by the Acer Technician absent sending the unit in for repair.
Googling the issue produced solutions involving various tasks including the "easy of access" settings for the keyboard, power button resets, the pin hole battery reset (on the back side). While there was a temporary resolution for all of the keys except the "n" key, the "n" refused to repeat until after the above PS/2 was removed and re-installed. Other of the above listed keys would start working again temporarily, but not continually.
We will see how long this fix last. It has persisted during creation of this post and reboot of the system.
Hopefully, this post will save other individuals the time and delay associated with this issue.