can't use to vpn since android upgrade to pie 9.0

[kawett]

Hello everyone,

I'm facing an issue since I upgraded my Xiaomi mi a2 lite to android 9.0.
I can't use my vpn anymore. When I try to open a page or something on my protected network it runs very slow. I'm able to send a few data, like ssh command, but I can't display my router home page.
When I try it on a older cell phone it works OK.

Does anyone is facing the same issue or know what should I try ?
I try to turn off battery optimization for this app but still doesn't work.
Thanks a lot for the help.

[dmachine]

I can't even connect since upgrading to pie. It was fine before pie, and still works on non-pie devices.