Weird recurring Wireless Latency on 6-9 minute intervals

Hi, I have the same issue with a Nighthawk X4S R7800 firmware V1.0.2.58.

Almost all the time at these specific hours, the router wifi have a problem :
XX:00:XX
XX:09:XX
XX:18:XX
XX:27:XX
XX:36:XX
XX:45:XX
XX:54:XX

yes,every 9 minutes, except between XX:54:XX and XX:00:XX, The routeur get "busy" for about 10~15 seconds, my TV freeze, Internet on pc lag, sensors over wifi lose packets etc.

Ok, you might think I'm fool, but I took about 6 hours of log, pinging every second the router and it is like a clock, almost each time, at specified hours, the ping take much more time, I did the log with wifi for about 5h30 and 30 minutes with a wired connection, Ican't draw a conclusion for the wired connection but it shown the problem at least once for the moment.

I unpluged every single equipment on my network one by one, so on the start of the log, all my equipment were connected, and at the end, there is only, my computer, wired to the router wich is unplugged from the internet.

I have dumped the configuration of the router if someone at Netgear can't reproduce it and want to try with my configuration (will send the file and tell the passwords by PM only to Netgear support).

in the log, ping with a time <1ms is when I'm wired (except when there is THE bug wich appeared only once, or glitches time to time) and those >1ms are with wifi connection.

I can't use QoS doesn't works for my android tv's boxes because the router doesn't see the traffic. They use a separated VLAN to communicate with the server boxes using unother set of ip address (not the same as seen in the router).

The log are pretty weird, so jump directly to the hour I quoted on the beggining.
important times to see in the log :
*wifi connection*
15:36:16 to 15:36:27
15:45:16 to 15:45:28
15:54:13 to 15:54:27
16:00:15 to 16:00:25
16:09:14 to 16:09:28
16:18:14 to 16:18:24
16:27:13 to 16:27:29
16:36:16 to 16:36:28
16:45:17 to 16:45:28
16:54:18 to 16:54:26
17:00:13 to 17:00:22
17:09:18 to 17:09:27
17:18:13 to 17:18:28
17:27:14 to 17:27:27
17:36:14 to 17:36:27
17:45:15 to 17:45:27
17:54:15 to 17:54:21
18:00:14 to 18:00:27
18:09:11 to 18:09:25
18:18:12 to 18:18:19
18:27:11 to 18:27:25
18:36:09 to 18:36:22
18:45:10 to 18:45:26
18:54:10 to 18:54:22
19:00:12 to 19:00:22
19:09:11 to 19:09:19
19:18:13 to 19:18:24
19:27:10 to 19:27:19
*missing 10 minutes of log here*
19:45:04 to 19:45:10
19:54:05 to 19:54:10
20:00:05 to 20:00:05
20:09:01 to 20:09:11
20:18:03 to 20:18:08
*wired connection, no bug seen at 20:27:XX*
*back to wifi*
20:36:04 to 20:36:10
20:45:05 to 20:45:10
20:54:03 to 20:54:09
21:00:02 to 21:00:10
*go back to wired connection*
21:07:40 to 21:07:45 <=not sure about it
21:18:03 to 21:18:08 < the only bug when wired if I don't count the previous
*going back to wifi a last time, only the computer is on the network since 20:30:00*
22:09:05 to 22:09:10

ok we clearly see that at the beggining the bug last about 10 to 15 seconds and at the end, it last only 5 seconds.

Equipment connected at the beggining :
Wired :
1 NAS
1 Odroid XU4Q

Wireless :
2 Androids boxes (freebox mini 4k)
2 Smart TV
2 Smartphones Android
1 Tablet
1 Computer
5 Raspberry Pi
1 Network printer
1 Google home mini
1 Robot cleaner
1 Wemos D1 mini (but it wake up only once by hour)
1 webcam

Can you fix this issue please ? It's been over a month now and it's very annoying. Also, I'm woried downgrading because I would have to re-enter all my parameters.

Best regards,
Kurairaito.