Hey Edina,
I can understand that one of the robots or some of the robots could have not been set correctly and that could be the reason that the account went negative.
There are a way that you can find which robots were the ones that made the bad trades. The easiest way actually is to check in the expert advisor settings and see the magic number or comment whatever you find in the inputs.
Hope that helps!
Let me know if you have any questions!
Kind Regards,
Nikos