Strange update: Starting a brand new world and planting a seed resulted in no achievement. Afterwards, I returned to an older save file to plant a seed, and the achievement popped up. Same for the "Chop Shop" achievement.
It seems that following achievements are not working. "Making a New Friend" "Chop Shop" (assumed) "In An Astroneer's Garden" I've planted many seeds to germination, and I've shredded many more than 50 objects. I am so close to 100% completion...