Very slow internet connection when VPN enabled

When i enable VPN on Blume 2, vpn clients have a good speed ( 160 Mb/s) , however client connected directly to Blume 2 has 1Mb/s ( via ethernet , no VPN)

How did you test the speed and what devices are connected (and by what kind of cable)?

Client and Blume 2 was connected by 8 pin ethernet cable , on VPN and on ethernet client i check speed by speedtest

There is only one LAN port, how do you test device with VPN and without VPN?

I connect 1 client though VPN ( open vpn). 2-nd client was connected by ethernet ( in that one port)

Brume 2 has only one LAN port. How do you connect two clients physically?

Physically was connected only 1 client, other one was connected by VPN

Maybe just replug the cable.

Only reboot helps. However when VPN is enabled i could not access to Blume via DDNS , so If i am far away i need to wait until come back home)