gpiomon does not show any events for GPIO

Question

I am trying to monitor a GPIO pin using libgpiod tools. The pinctrl has configured the pin as GPIO ACTIVE_LOW PULL-DOWN. Now when I read the pin using gpioget 0 5, I see the correct value getting retreived. So I expect the gpiomon to work the same way, i.e. whenever there is change in value (or rising-edge / falling-edge), the gpiomon 0 5 should show those events. But it does not, instead it shows nothing. Even when I read GPIO value using sysfs (export GPIO pin and read its value) it shows correct value.

When I run gpiomon with strace, I can see the timeout being reached and it keeps polling the GPIO pin.

mmap(0x6f6040b000, 262144, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x6f6040b000
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, 0x6f6040b000, 262144, "scudo:primary") = 0
ioctl(3, GPIO_GET_CHIPINFO_IOCTL, 0x7fc77d6ba0) = 0
mmap(0x702040e000, 262144, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x702040e000
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, 0x702040e000, 262144, "scudo:primary") = 0
ioctl(3, _IOC(_IOC_READ|_IOC_WRITE, 0xb4, 0x5, 0x100), 0x7fc77d6ab0) = 0
ioctl(3, _IOC(_IOC_READ|_IOC_WRITE, 0xb4, 0x7, 0x250), 0x7fc77d6990) = 0
ioctl(3, _IOC(_IOC_READ|_IOC_WRITE, 0xb4, 0x5, 0x100), 0x7fc77d6850) = 0
ppoll([{fd=4, events=POLLIN|POLLPRI}], 1, {tv_sec=10, tv_nsec=0}, NULL, 8) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN|POLLPRI}], 1, {tv_sec=10, tv_nsec=0}, NULL, 8) = 0 (Timeout)

What I wanted to understand is:

1. How does gpiomon monitor events? Polling or interrupt? If it's interrupt based, how does gpiomon get to know which interrupt line is there for this GPIO?
2. Is there any dependency on pinctrl? Like do I need to configure the pin something like external interrupt to make it work with gpiomon?

[Edit 1] output of the gpiodetect and gpioinfo: