Your current new loan will be 3rd housing loan which is only eligible for 70% margin max.

In order to obtain higher margin, the housing loan that you joint name with your brother must be taken out from the facility before you start to apply the new application. Otherwise, same issue which is 70% only

FYI, bank only refers to CCRIS report, which it shows how many housing loan you have instead of how many properties you owned.

Thanks