Update Cell in Another Sheet - No Parameters

Good afternoon,

I have taken Smartsheet courses and scoured both Google and this forum trying to find, what I think, is likely a simple fix/answer - but I cannot find it.

I have a date column on one sheet (Start Date, in this instance) that triggers (copies a row) to another sheet when a box is checked. If the Start Date updates after the trigger, it - of course - never updates again, or it would duplicate the row on the other sheet.

Also, the date could be any date in the future. I cannot change it to "any update" or it would push the second it is entered - which I don't want - and I cannot possibly know what future calendar date it might be to use that date to trigger a push - which would still result in duplicating the line.

I would like to have a formula or create some sort of trigger that, if the field "Start Date" is updated - it pushes that information to the matching cell on the other sheet. I tried "links" and that did not work.

Happy to learn / study but I don't want to go all the way through every course and never figure otu how to do this. Thank you in advance for your help!