Slitherine

I read that supply get lower, thats ok. But I also noticed it gets lower between saves.

An exampel I start with 68 in supply at turn 1. Then i start turn 2 i have 67. If I now save the game to something else and later start my game at turn 2 the supply was now 66.

And since I often can only play 1 turn at a time, my supply net after a while was someting like minus 30. So my units moved slowly and couldnt nearly fight.

Is it supposed to be like this?

I tried to replicate this situation with a lot of playing and saving and restarting the game but every time it just works as it should. Not sure if it can have anything to do with not capturing the supply base but even then a saved game should give you back the same situation as you had before saving. Did you find any answer yourself?