Hey Dan,
The “global slot” setting is not directly related to pattern storage, it’s used
to manage system settings. So i think you might be getting slightly confused.
You need to focus on the snapshots.
Each individual snapshot contains 16 Patterns x 8 banks + 64 Kits and are completely separate from each other. Each snapshot contains 8 global settings as well (but don’t worry about that for now)
When you change or load a snapshot you are reloading all the patterns and kits in the MD, with those that are stored in the selected Snapshot.
It’s possible that you have changed snapshot and the pattern/kit you made last night are in a different snapshot.
Snapshots are not automatically saved, you need to save them manually before Loading another, or use the Snapshot Quick Mode Menu, with the Global +drive Quick Mode setting set to “Change”.
Have a read of the Machinedrum +drive manual.
There’s a bit to read, but it’s fairly easy once you understand.