When I have
2-Over a long period
the returns of the last few years get wrong and super small
In the picture you can see what happens to the last few years. The smaller table has the correct returns. The large table has correct returns for the first years and then they become all wrong. Before you ask of course its the same system and if you look some of the years even show the exact same return
Results are correct and AmiBroker just has shown you that your expectations are unreal.
Please open up the manual: http://www.amibroker.com/guide/w_settings.html
Scroll down to "Portfolio Tab: Limit trade size as % of entry bar volume" and read the portion of Users' Guide referring to that setting.
Putting zero does not solve the problem. It just hides it.
Problem is not with AmiBroker but with your expectations to be able to compound ad infinitum.
You do realize that the protection against too large trade size with respect to bar volume is in place for a reason?
You can't trade more than 10% of bar volume without HUGE amounts of slippage?