Cyclone 5 SoC FPGA Bank Supply Prerequisite

Dear Altera Support Team,

I am not sure this is correct and did not found much info on Handbook.

Device 5CSXF6C6U23

CASE 1: BANK 5A 5B only supplied VCCPD to 2.5V and VCCIO is floated.
JTAG scan chain shows both HPS and FPGA devices.
JTAG program shows failed with wrong device address.

CASE 2: BANK 5A 5B supplied 2.5V or 1.8V VCCIO.
JTAG scan chain shows both HPS and FPGA devices.
JTAG program shows successful result.

Based on the above situation: do BANK 5 must supplied VCCIO in order FPGA to work?
I don't understand, other brand FPGA do not have such requirement while VCCPD must be powered which is understandable.

Please confirm this for best and safe device HW configuration.

Thanks,
Brian