If yours are new, call HM. They have a 12 year warranty. Mine don’t qualify since I’m not the original purchaser. Odd that yours have a wobble too since so new.
I can CFM the original had the spacers as part of the same cast aluminum as the arm. It’s like that on my Soft Pad Group desk chair which is from the 80’s.
Oh, also, BTW I just found out that in the lounge chairs, they just returned to the original 4 star base. I believe it was originally designed as 4 star, at some point (I have an 80’s HM catalog) it was offered as both 4 or 5 depending on the model, then recently was only in 5 star. Now back to 5.
I believe the desk chairs are still only 5 star though originally 4 star. Think it’s a law of some sort to prevent tipping. Not sure when that came into effect.
R