split payments declined on Square Terminal

[Smithward]

when splitting a payment using Terminal, if the 2nd (or later) payment in a group is declined, there is a dialogue about keep/cancel the entire transaction (which suggests including the already 'successful' prior payments). 

can someone confirm what is actually happening? if one of the payers is declined, are all the previous payers payments on that ticket also cancelled despite being 'approved'?

[VanKalkerFarms]

Without having gone thru the exact dialog I believe you will still have the first parts approved and have the option to try again after hitting keep on that dialog box you are referring to.  I have not had this exact scenario so I can't confirm exactly.