A6210 WiFi cannot find the 2.4GHz router

[HDKD]

My A6210 adapter works perfectly when I'm connected to my Netgear EX2700-100PES N300 Wi-Fi Repeater or Netgear R6120-100UKS AC1200 router.

Now, I'm trying to set up my computer with a D-Link router model DIR-655 which functions only 2.4GHz. Although my laptop, another Asus network adapter and my phone can detect the router, but A6210 does not list it among detected networks.

The router is compatible with IEEE 802.11b/g/n. The manula of the router is available here: DIR-655_manual_A2_101_DI.pdf (dlink.com.sg)

I have reset the router, still not listed in Netgear A6210 Genie. Please help me figure out what could be wrong.