Resolve unexpected Function (F1 – F12) or other special key behavior on …

The F LOCK key switches between the standard commands that are labeled on the front of the keys, such as F1 or INSERT, and the alternate commands that may or may not be labeled on the keys. When the F LOCK light is on, the F LOCK key is on and these keys perform their standard commands.

https://support.microsoft.com/en-us/topic/resolve-unexpected-function-f1-f12-or-other-special-key-behavior-on-a-microsoft-keyboard-68d68eed-b65e-09ab-1601-e6b59092dbda