I am running Joomla 3.10.11 with SPB 4.0.3 in test lab (coming from SPB 3.8.8). In SPB 3.8.8 all images are stored and sorted in folders.
If I start the media manager (SPB 4.0.3) I can see All Items, Images, Videos, Audios, Attachments and Folders as buttons at the side. All selections are working fine excapt the Folders button. If I click Folders for a short time there is the message "No Icon found" and then all Elements of the Media Manager are gone.
https://www.dropbox.com/s/ons96tx1b7tiw8d/Media_Manager_all_items.jpg?dl=0
https://www.dropbox.com/s/uj71timovcb6plb/Media_Manager_Folders.jpg?dl=0
Best Regards