Some devices lost connection when VPN is on

I am using MT3000 fw 4.8.1, VPN on wireward

I found that when i use VPN on some devices (i set only some devices to use VPN) some other devices will lose connection or no internet connection. It does not happen on all devices not using VPN but only a few and these devices can not have internet, there are only 2 ways: 1 is to turn off VPN or 2 is to put them on VPN. is there any way to fix this?