Stick pistons don't work vertically retracting blocks. They work laterally but only push blocks vertically, they do not pull them back to the collapsed position. This seems to only happen when used as a circut as shownin the picture attached. It works when used in a simple circut when there is direct input.
Hope this is helpful.
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We're tracking this issue in MCPE-96088, so this ticket is being resolved and linked as a duplicate.
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