The time of sending e-mails within one campaign is TOTAL for all sequences. This means that when setting the send time for the second e-mail, you have to subtract the time set for the first e-mail.
Example 1: if the first e-mail is to be sent after 2 hours and the second one after 10 hours after an event occurs, set the time of the first one in the sequence to 2 hours, and the second to 8 hours.
Example 2: if the first e-mail is to be sent after 1 hour and the second one after 6 hours after an event occurs, then in the first sequence set the time to 1 hour, and in the second to 5 hours.