I just upgraded my LG V20 (H918) phones to LineageOS 19.1 and all is working great except when I restart my phone when using a VPN with the “Always-On VPN” setting and “Block connections without VPN” setting is enabled, my phone cannot access the internet. Therefore my VPN cannot connect to its VPN services and connect to a VPN server. The only way to connect to my VPN from this point on is to disable “Always-On VPN” setting and “Block connections without VPN” setting and reboot my phone and then it will be able to connect to the VPN server.
I did not have this issue before. And I do not want to disable “Always-On VPN” setting and “Block connections without VPN” setting since this acts as a built in Android VPN kill switch.
Your description seems to match an open issue in lineageOS.