Recommendation for OpenSprinkler maintainers:
(1) Update your 2.1.9 (3) upgrade instructions today to mention the need to change this “Advanced Setting” to 0 when upgrading.
(2) Make future firmware versions and/or config UI versions reject and highlight as bad the known bad former default pre-configured NTP server IP Address. Anyone with that value set is just going to have a bad (offset) time and will either abandon opensprinkler or be reaching our via support tickets and forums.
I made a PR proposing one possible way to tackle (2) on the firmware side of things. https://github.com/OpenSprinkler/OpenSprinkler-Firmware/pull/128