This is not a bug. This was part of the May 31, 2023 Worker Update Patch: https://www.naeu.playblackdesert.com/en-US/News/Detail?groupContentNo=5345#Major,
Worker Exchange Additions and Increase of Standard Price
- The standard sales price registered in the Worker Exchange for each level of workers has been added/raised as follows.
- However, Papu and Fadus workers, which can only be hired in Kamasylvia, will no longer be available for sale at the Worker Exchange.
Since Kama workers cannot be sold on the Exchange any longer, you will have to fire them if you would like to roll new workers there and do not have any additional lodging available.