Dead by Daylight is no stranger to various issues relating to its gameplay mechanics or server problems, but while these are usually not the players' fault, some others might be a form of Dead by Daylight cheating!
Dead by Daylight lag switch is an ongoing issue that's brought about by an excessive amount of ping on host's end, causing recurrent lag spikes for all other players which, in turn, are then easily picked off by the killer.
If you're asking what is Dead by Daylight lag switch, you've come to the right place. This is a problem in many different games, though it is definitely exacerbated in Dead by Daylight due to the following: a) killer is always the host, and b) the game is asymmetrical, where all but one player have little to no combat agency.
In practice, this means that killers can sometimes purposefully downgrade their own connection speeds to incur lag switching, so as to more easily take down other players, who no longer have full control over their in-game avatars. Is this a form of Dead by Daylight cheating? Damn right it is.
Be sure to check out how lag switching works in practice by watching the video embedded below this paragraph. Have you had any experience with this? Do you think it was done on purpose?