I am using Moodle 3.9.2+ and Adaptable Theme 3.0.2.
Until few days ago I could see the administration blocks, both Course Administration and Site Administration.
Yesterday they disappeared from users' accounts and later even from my admin account.
I tried many tips suggested on the forum but without success.
Using Boost or Classic Themes the Administration Blocks appear again, so I suppose it is a problem with the Adaptable Theme.
Unfortunately I have prepared many videos to teach users how to use Moodle, and I used the Adaptable theme. Now the UI is different and users cannot understand what I show in the videos.