Not sure if its the same issue that you all are reporting with your 7u spacebars, but mine seems to be quite rattly and I can't quite figure out why. It doesn't seem to have any issues returning, however, like others have mentioned, it's just really noisy. For the record, I've used GMK, CRP, and OG Cherry 7u spacebars on the same board without issue, so this is unique to EPBT as far as I can tell.
Edit: I've already lubed the stabs themselves with 205g0, and there is no rattle with the aforementioned GMK, CRP, and Cherry spacebars.
Edit2: Checked again and the teal spacebar is just fine but the grey doesn't return completely (turns out I was incorrect before) and also rattles if pressed near the center of the spacebar. This is while using 55g linears.