The Semtex in Call of Duty: Warzone is a great counter weapon to an enemy rushing you with a Riot Shield, or just trying to get up close to your for a kill. However, a huge counter to it was just discovered and posted online for the entire community to see, potentially creating an accidental nerf to the Semtex.
In the Reddit post lined below, user u/LordTexugo posted clips of the strategy they discovered while playing the Warzone to the r/CODWarzone subreddit. In it, u/LordTexugo is carrying the Riot Shield which is required for this mechanic to work, and chasing down enemy players trying to get a melee kill on them. Each of the enemies respond by throwing a Semtex back at u/LordTexugo hitting them in the Riot Shield. Typically this would be a death sentence, as there was no previously discovered way to remove Semtex after it got stuck to your body, and it would explode and kill you within a few seconds. However, in each clip, u/LordTexugo immediately drops their shield, which detaches the Semtex from their player, picks it back up again immediately, and uses it to shield from blast damage from the Semtex that is now sitting on the ground. u/LordTexugo then chases down their enemy, and gets the kill.
It's unclear if this is an intentional strategy left in by developers to counter the Semtex, or an uninteded consequence of the current mechanics of the game, but it is sure to be a maneuver that players start practicing immediately, to gain one more option for their bag of tricks to stay alive and fighting for as long as possible.