I tried to defuse in custom game and the range and was unable to drop my guns without canceling the defuse. There doesn't seem to be any mention of a change to that mechanic in recent patch notes but maybe I missed it.

When we first make a new account, it is known that your unrated games do lead to how Valorant decides your skill level for competitive. While this makes some sense, as Valorant has to determine your skill level before you do your placement...