Whenever I play with my friends on multiplayer, even when playing on small maps like construct, after a while of being in one game a delay happens for everyone but the host. This means they have to wait to spawn things and get weapons. On larger maps theres an immediate delay
If the server is not dedicated, its the host's game starting to become very laggy, so it starts causing major delay. Else if it is dedicated, the server doesn't have enough resources and there may be some addons that after awhile start to make the server lag. Try and see what addons are causing this issue, or try to just restart the server every once in awhile