MT300N-V2 loses internet when VPN starts

when I try to activate the VPN, the router most of the time will disconnect from its server and I will no longer have internet. Usually, it will reconnect but by then the VPN has gotten an “unreachable” message. Other times I have to do a rescan to get it to connect. Then if I try turning on the VPN, it disconnects again. Once in a while, it will work and will stay connected to the internet.
I have to go back and forth between trying to turn on the VPN and reconnecting the router to the internet until I get lucky.

running openwrt-mt300n-v2-3.104.bin.

can you give more details:

which is your vpn service provider?
are you using openvpn or wireguard?
Is it a public wifi or your own private wifi?

Finally when this happens, can you get the log? You can get the log in luci or ssh to the router and use “logread”

Service provider is Torguard

Using OpenVPN

Happens at home and at hotels. Don’t normally have my computer when in area where there is public wi-fi so I don’t know.

The wi-fi will be connected. Then I’ll go to VPN client and select CONNECT to bring it up. I’ll get “network is unreachable” messages. If I go back to Wireless menu, it will show no wi-fi connected.

Note that for my home networks (regular and guest - same router) as well as other trusted networks (like where I volunteer), I have enabled “reconnect” so it will restart wifi. However, for security purposes, I never auto-reconnect hotel or other wifi sites so I have to rescan to make it reconnect.

For the home and trusted networks, after a number of “network is unreachable”, the automatic reconnection will eventually become successful and the VPN will connect. For non-autoconnect sites, I will have to repeatedly rescan and reconnect to finally get the VPN to come up. Once the VPN has connected, it most always stays on with no wi-fi disconnects but for some places (possibly weak signals) it happens again.

With the latest GL software version openwrt-mt300n-v2-3.104.bin and the latest TorGuard-provided OpenVPN software and config files, the problem on my home network is not as bad as it used to be. In repeated tests, I would get 3 “network is unreachable” messages and apparently only one disconnect before the disconnects stop and the VPN connects.

It will be a while before I connect to any hotel networks. I will try and post logs for my home network when I try it again.

Note that I don’t use the MT router at home except for updating it or verifying it works before going on a trip. Both my linux machines and both my Android phones have VPN software and I have not noticed any problems like that with them connected directly to my home router.

Also Note that it happens whether I use LAN connection to the GL or wi-fi to GL but in all cases, I use wi-fi from the GL to the other router.

I had the exact same problem and I lost a day trying to fix it , basically firing the vpn from a wifi client resulted in wifi loss due to vpn activity/handshaking and problems with the vpn setup process (network unreachable). I tried to do the same connecting via ethernet and everything worked . I was about to return the router but then I simply did a factory reset + fresh configuration and then everyting started working as expected (!) I had the same random wifi loss but then the vpn handshaking was so fast that everything worked