DNS cannot be resolved issue

RouterOS Beginner Basics
1

Hi all, I’ve been on this issue for a very long time.

The gist of it is that sometimes my clients are not able to connect to the Internet.
The thing is they are connected to the LAN via APs, got assigned an IP address and displays the correct gateway when I checked.

But sometimes randomly around the office, some clients will just drop their internet but remained connected to the AP.
The error shown in Chrome is that DNS cannot be resolved, which is true because when I pinged 8.8.8.8 from the client, all timeout.
But when I pinged it from RouterOS, I’m able to get a response.

2

In times when client device can’t connect to DNS server at 8.8.8.8 … can client device ping its default gateway (which is your internet router I suppose)? If not, can it ping AP (for that, AP has to have IP address configured and at least ICMP has to be allowed)?