Orbi SXR30 DHCP and Internet access issue.

Hi,

Just bought a kit with a SXR30 and two sattelites two days ago.
I'm really happy with the coverage but...

First issue, qome times, DHCP takes over 2 or 3 minutes to give an IP.
I've tried to "renew" IP. But nothing is working. It's like the DHCP service has stopped. Nothing in the event viewer of the router.
If I use the DHCP of my NAS in place of, it works very well every time.
Same issue, get the "pc" out of standby and didn't get an IP.

Second issue, is randomly, only one device cannot access to the internet.
Gateway is good "10.11.12.1", mask also.
I noticed that when the device cannot access the internet, it cannot access to the web page of the router BUT IT CAN access to the lan like my NAS or other computers.
So no internet, no access to the router, but it can access the NAS and the nas is wired to the router. 
I got this issue with my laptops, and my apple TV that is wired.

Rebooting the router solve this issue. But it came back after a few hours.

This night, this issue occured on my iPhone. I took my Macbook and check the internet connection and it was good.
I've checked, and both of my devices was on the same access point (satellite). So this is not a problem between access point and router.
I've downloaded a file from my nas with my phone at a really high speed but no internet connection.
Diconnected the phone, reconnected it and still the same.

I'm really disapointed. Don't know what to do.
I didn't get this issue before installing the app Insight and saving my router on my netgear profile.

Tech information :
Router : 10.11.12.1
Gateway : 10.11.12.1
Mask : 255.255.255.0
DHCP IP Range : 10.11.12.100 to 254
First 99 are used for my reservations like my nas and my printers.
Satellites are wired

Thanks for your help

Edit : found this :https://community.netgear.com/t5/Orbi-Pro-WiFi-for-Small-Business/If-your-Orbi-Pro-SRK60-SXK80-started-having-frequent-client/m-p/2074927#M3292
And disabled traffic monitor for testing