Never ever combine multiple services to the principal account holder. This is considered supplementary service to the system.

Example, U have mobile and fibre under the same telco and account name.

To port out, U will need to split the services individually. Once done, they only port out.

I have this problem before when porting out from Maxis. In the end, I ported out to U Mobile for telco and fibre is DiGi. Never ever combine services despite whatever promises given by the sales rep.