Our DM cast web on us, and we were all asked to make saving throws immediately. He said, "Otherwise you’re all like Schroedinger's Cats waiting to see if you’ve been caught or not" (which affects attacks on us).
However, those that weren't restrained had to make saving throws again at the start of our turns (no problem with that since the rules clearly specify).
It is difficult to argue with our DM that we shouldn’t make saving throws when it is first cast.
When should we make our first saving throw?