Are you sure this is the correct one? There is another underground one few meters away.

This one is tagged as a historic one  which is also a base for a lantern, like shown here: https://epoznan.pl/news-news-153129-w_calym_poznaniu_sa_takie_tylko_trzy_jeden_wlasnie_zyskal_odnowiony_element. While I can see it in a Google StreetView photo from 2021, the linked article mentions that only three remain in Poznań, neither of which are on Matejki. Has this one been removed?