Hello Nelly, I would be happy if you could measure whether the glass can be pushed into the profile to a total of 118 cm.
As far as I can assess, this did not go "wrong," but is quite normal. The shower tray is simply installed first and then tiled. And so only about 118 cm remain.
I asked about it today in a bathroom studio... and yes, normally the profiles compensate for about 2-3 cm exactly for that reason. That would also help me.
Maybe Nelly can confirm that.