i had recently problems, so i configured the windows service to restart after 2minutes more than the checking interval of uptimerobot, so it get the downtime registered when sleeping and missing the alarm.
eg: restart after 23 min and uptimerobot checks every 21 min. so i could minimize the data loss after 4h offline.
automatic updates are not affected by this, an continue normaly. (restart service after 1min maybe to short)