No worries. Great software and support, which are both found with this software and community, are much appreciated.
After reloading a snapshot I tried the suggestion offered by hasse_basse1 by only having the one line below in interfaces.
source /run/network/interfaces.d/*
This change worked after a reboot, so I went ahead with the Webmin 2.011 update. Update completed and it seems that everything is back to normal. In my case with AWS LightSail, this is the correct solution.