Looks like a right mess.
Shower door instructions NORMALLY have the sealant applied to the outside for a few cm up from the base. This allows water to run down inside the not sealed parts of the fitting, and then leak into the inside of the shower at the bottom as the outside is sealed. Yours is clearly sealed on both sides. I guess if the inside has more (ie higher) gloop - then the water that runs down goes out rather than it, as the inside of the fitting 9or it's spaces anyway) is itself full of water.
Why not download the fitting instructions for your shower and compare to the photos :-)