Thank you for sharing these details with me. I reported this as a new issue yesterday to the development team and from what I can see, they're investigating it at the moment. I will keep you guys updated about the situation Apologies for any inconvenience caused.
Hey folks! For those of you that are still encountering this issue with throwing/attaching grenades, please make sure you have the correct Specialization activated for the grenade type you're trying to throw, as this was confirmed to cause the issue for TheModfatherInc.