As this video shows, sometimes inputs are registered late or not at all. This effect can usually be observed when hitting multiple keys at once.

(Ignore the fact that some keys are not picked up correctly by the keylogger, it pulls events directly from the input device and seems to translate certain keys codes incorrectly. Like m turns to n, n to b and some others. Though i confirmed that a,w,s and d are logged correctly)

Edit: Reproduced issue on default key settings

Edit 2: It was suggested that this could be LWJGL3's fault, see this StackOverflow post