Ubuntu 18.04 - networkmanager dont show other wifi after few minutes

[lnly]

how to reproduce:

dd the iso to an usb drive and boot from it.
List all wifi devices in live-mode and connect to one of it. Use the web for some minutes. Open up the wifi on the top right again and list the available networks - it dont show any others any more. Just the one you are connected to.

How to overcome the bug: put the computer into airplane mode and go away from airplane mode again. Or: disconnect the usb wifi device and connect it again.

Does this bug exist also on installed 18.04 and updated to last (apt update, apt upgrade, apt dist-upgrade)?
Yes

What wifi device is been used:
ieee80211 phy0: rt2x00_set_rt: Info - RT chipset 3572, rev 0223 detected
ieee80211 phy0: rt2x00_set_rf: Info - RF chipset 0009 detected
ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
usbcore: registered new interface driver rt2800usb
...
ieee80211 phy0: rt2x00lib_request_firmware: Info - Loading firmware file 'rt2870.bin'
ieee80211 phy0: rt2x00lib_request_firmware: Info - Firmware detected - version: 0.36

uname -a
Linux t 4.15.0-20-generic #21-Ubuntu SMP Tue Apr 24 06:16:15 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1769480/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1769480

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[lnly (eltz)]

There are no usefull logfiles. Either dmesg nor syslog show anything usefull.
I am connected now. Problem exists like always.

dmesg only show the mac-addresses (privacy) that its connecting to.

syslog only show no errors. Just:
NetworkManager[804]: <info> [1525771468.8177] manager: NetworkManager state is now CONNECTED_GLOBAL
systemd[1]: Starting Network Manager Script Dispatcher Service...
dbus-daemon[758]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service' requested by ':1.14' (uid=0 pid=804 comm="/usr/sbin/NetworkManager --no-daemon " label="unconfined")
systemd[1]: Started Network Manager Script Dispatcher Service.
dbus-daemon[758]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
nm-dispatcher: req:1 'connectivity-change': new request (1 scripts)
nm-dispatcher: req:1 'connectivity-change': start running ordered scripts...
whoopsie[934]: [xx:xx:xx] online (i removed the time)

It then synchronised with the time and that was it. Not a single error in the logfile.

[Kai-Heng Feng (kaihengfeng)]

Sounds like a driver issue. Can you attach dmesg when this issue happens?

[lnly (eltz)]

I dont know what you mean in dmesg. There are really no errors. I have posted all relevant messages from dmesg. In the first post the wifi chipset and driver are listed. What additional information is required?

[Martin (martin615-n)]

Is there any chance to reactivate that topic? I have the same issue on a fresh Lubuntu 18.10 installation on my Sony Vaio Notebook.
After 5 minutes the tray icon (nm-tray) only shows the current wifi connection (which still works), no others anymore.

[Kai-Heng Feng (kaihengfeng)]

Do you see the list via command `iw`?

[lnly (eltz)]

I dont thought this thread would get a response. I asked first what information i should provide but did not get any response because in dmesg there is nothing relevant. Its sad that someone else have to say that he have the same issue to get a resposne.
I installed ubuntu 18.10 in the meantime on an other device with totaly different wlan chipset. Same issue. So not that even the ubuntu version, also the hardware changed fully.

Scanning via command line:

iwlist wlan3s0 scanning
wlan3s0 Interface doesn't support scanning.

Lets see if this issue wont get touched again until someone reports the same issue with 19.04.

[Kai-Heng Feng (kaihengfeng)]

I still don't see any log attached here. Maybe try tweaking powersaving knob in NetworkManger config file.