Wifi 5/6 dropped randomly if ipv6 is enabled - Bug dhcp6!!!

Updated: 19.12.2022
#####################

Hi Support

at startup of analysis:
Wifi5/6 dropped randomly if ipv6 is enabled/disabled on gnome-network-manager-gui no Error on Logs! No red Kernel Messages.

My Lab:
At my Lab i disabled all ipv6 on my Subnet LAN Openwrt-Routers, and my Laptop loses "randomly" 20times a day the Internet but the Signal is 100% to the WIFI-Routers, no ping, no nslookup to first DSL-WAN Router possible.

First Handling:
After i manual enable/disable WIFI by switch is works again fast.

Analysis:
After some search on Net i disabled ipv6 in sysctl.conf !

GTK-Apps Affected: seen on network-manager/network-manager-gnome/wicd Managers

Hardware Change/Test:
I tested / changed 3 different old wifi-5+ new wifi-6 intel AX 7260 HMW mini-pci-cards same problem!

Now testing again..

Thanks
Linuxonlinehelp_eu

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: network-manager 1.10.6-2ubuntu1.4
ProcVersionSignature: Ubuntu 5.4.0-135.152~18.04.2-generic 5.4.212
Uname: Linux 5.4.0-135-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.9-0ubuntu7.28
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sun Dec 18 11:24:20 2022
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2021-08-19 (486 days ago)
InstallationMedia: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
IpRoute:
 default via 192.168.71.1 dev wlp3s0b1 proto dhcp metric 600
 169.254.0.0/16 dev wlp3s0b1 scope link metric 1000
 192.168.71.0/24 dev wlp3s0b1 proto kernel scope link src 192.168.71.123 metric 600
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
WifiSyslog:

http_proxy: http://127.0.0.1:8118/
modified.conffile..etc.NetworkManager.conf.d.default-wifi-powersave-on.conf:
 [connection]
 wifi.powersave = 2
mtime.conffile..etc.NetworkManager.conf.d.default-wifi-powersave-on.conf: 2022-06-30T19:17:37.737049
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
 wlp3s0b1 wifi connected /org/freedesktop/NetworkManager/Devices/3 AXWIFI71 bec4545b-24e6-40ef-a933-43121b9b819b /org/freedesktop/NetworkManager/ActiveConnection/3
 enp2s0 ethernet unavailable /org/freedesktop/NetworkManager/Devices/2 -- -- --
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/1 -- -- --
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.10.6 connected started full enabled enabled enabled enabled enabled
no_proxy: