Hi, giving Maki the potion is implemented. Did you get the Luna's potion, then go to sleep, and finally talk to Maki?
If you have done this and still have the problem, you could send us your save file through one of our social networks.
The save file is stored here:
- PC: {Game_Folder}/saves/
- Android: /storage/emulated/0/Android/data/com.huh/files/saves/
- Android: /storage/Android/data/com.huh/files/saves/