Strange delivery order when using SBDScheduledUserMessageParams

I’m using SBDScheduledUserMessageParams in order to schedule and send 2 messages directly after each other. In SBDScheduledUserMessageParams only minute selection is possible (not seconds). The code (abbreviated):

let params = SBDScheduledUserMessageParams(message: textA, year:fireYear , month: fireMonth, day: fireDay, hour: 10, min: 00, timezone: timezone)
let params = SBDScheduledUserMessageParams(message: textB, year:fireYear , month: fireMonth, day: fireDay, hour: 10, min: 00, timezone: timezone)

Both messages (textA and TextB) are scheduled at the same time (10.00). But scheduling the messages like this, sometimes textB is being received before textA, and sometimes in the other order. I would like to maintain the order of textA before textB on the same time (or almost the same time). Is there a possibility to do this?