As the CONFIG_SEL pin in Intel® MAX® 10 devices is a dual-purpose pin, it is equipped with an internal weak pull-up that is enabled by default before user mode.
Based on the values of the internal weak pull-up resistor in Table 17 in the Intel® MAX® 10 FPGA Device Datasheet, under some conditions, a 10-K Ohm external pull-down may not be strong enough to result in a logic low, resulting in the image not loading from CFM0 when the CONFIG_SEL function is enabled.
If you are affected by this issue, you can equip a stronger external pull-down resistor (e.g. 1-K Ohms) on CONFIG_SEL.
Alternatively, you can disable the option “Set I/O to weak pull-up prior user-mode” in the .icb settings.
Note that this will disable the weak-pull up during configuration for all general-purpose I/O pins too.