Poker 2 has Cherry stabilisers (right?).
When you remove the space bar, it is normal for the stabiliser bits to stay down. It is the force of the spring in the space bar switch that, when a space bar is properly inserted, brings both switch and stabilisers (and space bar) back up to the top of the stroke.
When you put the space bar on, make sure it is firmly pressed down on each side. You'll know if one or both sides aren't fitted properly as the space bar will not be flat, one side will be higher than the other, and/or it will rattle from side to side.
Also Cherry stabilisers are somewhat unforgiving for even minor variations in stem placement under the space bar. If you can, definitely try a different space bar (particularly the stock space bar, if you still have it).