The problem is that you are trying to apply the "hot sustained" method over a non-linear system. In this case your results may be not the one that everybody expect. For example in the attached file you may note that even if you actually do not have lift-off supports you have different results for "sustained" and "hot sustained". I expect that it shouldn't be any difference but it is.

Therefore in case of non-linear systems, use other method.

Best regards,