@domi I guess, they will probably clear this data at some point but until then it will be like this (the situation was the same few weeks ago). There is also a group of buses in one area (these ones are all buses that have been withdrawn from use) and one guy told me that there is a warehouse there of one company which does something those buses and that's why they are all shown around here (signals there are also from 2024). And there are also some old signals from bus depots. The API is here
https://api.um.warszawa.pl/ (beautiful website btw xd)