Yes, It's recommended for maximum security. I don't know how your GUI looks like at the moment, but with the 2013 FW the Region is selectable like in this screenshot:

@DocDam Try configuring wireless security like this (both bands): and wireless settings (2.4GHz band): and 5GHz (Channel Width - Auto): Ensure you have selected your country in the Region dropdown...

Use Access Control instead of Parental Controls for this configuration.

@monirprince07 You can add ports in Virtual server menu (for example): or port ranges (for example): In DMZ you can add only one IP address (for example):

One more thing you could try @home - if you have a power adapter with similar parameters like the original one, you can swap them to exclude the possibility of an adapter issue.

@DocDam Since when you are experiencing this issue ? Even before upgrading the router's FW? Have you made any changes to your local network recently ?