it will loosen up overtime but not much.
also, check that there a no burrs around the edges of the mag release, inside the mag well. It there are burrs even a little one, you will have to push the button further to clear that out of the way in order to let the mag out.
sometimes these deform during installation (while trying to push the catch spring into the gap). If you had rough installation, then check for any rough edges.
There is a way to install these with minimum effort and it all requires a metal pick, like the dentists use. if you use a screw driver it will most likely slip and make a dent somewhere inside the mag well (most likely in the V shaped gap for the catch spring). It is the 1911 stupid scratch but for Glocks, lol.