The manual's steps work for my Shield RE-assembly:
move Take Down Lever in vertical position. Guide the slide to the rear and lock.
Move TDL into horizontal and release the slide forward.
on my mp9c
When I guide the slide onto rails the TDL starts moving upward and If I don't
yank the slide fast enough rearward, the whole thing locks up.
I've examined the guide rod and take down lever and don't see any obvious problems with either.
move Take Down Lever in vertical position. Guide the slide to the rear and lock.
Move TDL into horizontal and release the slide forward.
on my mp9c
When I guide the slide onto rails the TDL starts moving upward and If I don't
yank the slide fast enough rearward, the whole thing locks up.
I've examined the guide rod and take down lever and don't see any obvious problems with either.