MiniMODs Alloy Seat Post for Brompton - Black - 560 x 31.8mm

I like this seat post, it's much lighter than the factory fitted one and the grooves do help to prevent slippage, but I've found that the lip at the bottom of the post is larger than the one on the standard Brompton seat post and it seems to get stuck on the Brompton Advance Rear Frame Locking Block when folding my P-Line. The lip blocks the seat post from lowering and therefore prevents the bike folding properly. I've managed to get the post through with force, but that's not ideal and not something I would want to do every time I fold the bike, so unfortunately I can't use this seat post on my P-Line.