You also find that if your coming from the right or left the 110 single socket that the 110 to geberit hdpe adaptor fouls the frame.
This can be overcome by either cutting a chunk out of the frame leg with a grinder or using a large ofsett multiquik with a sliver of 110mm pipe.
All the grohe frames foul this way as did the poncey Turkish one I fitted last week. Sometimes the geberit works if you adjust the adapters out.
Been up against this many a time.
The bottom Geberit fitting is meant to go into a "ring seal" socket on a 110mm pipe and not into straight pipe or a solvent socket... It is not made of abs and solvent doesn't work on it... The simplest solution is to buy the cheapest mcalpine pan connector and just use the white finned rubber reducing gasket to go into the 110mm soil pipe with the geberit to waste adaptor (bottom in your photo) into that.