The only fix I found is uninstalling Radmin and then reinstalling and then again uninstalling it. That fixes the "no internet access". This is the same problem as this post: https://radmin-club.com/radmin-vpn/radmin-vpn-make-my-ethernet-not-connected-but-somehow-the-interne....
Try to change metric of Radmin VPN adapter. Firstly, set it to 1. If it didn`t help, set it to 1500 or to the max value (you can read more here https://www.raymond.cc/blog/choosing-which-connection-to-use-with-windows-routing-table-editor-gui/).