Reinforcements don't show up in my scenarios at all.

I have tried everything now but for some reason, in every single scenario I make, there is no reinforcements even if I have setting on low, medium or normal. They just don't work. I can have the first turn reinforcements on and they work but every single time after that when you should get them you don't. The same problem persists even after I started again from a scratch with a new scenario where I didn't change a thing.

I think the problem only occurs when you have the option 1st turn reinforcements unchecked. I just checked it on your scenario and got the reinforcements as usual. So for now just make sure to always check the '1st turn reinforcements', the problem will be fixed with the next update.