I'm always try to get an extra trip or 2 just to make sure.I contacted support about it. They said for the time periods I missed the guarantee I was off by a few minutes. So I worked three hours and completed three trips. The requirement was 1 trip per hour but apparently I stayed online for an extra minute or two. That is very annoying and I think unfair as the clock can always be off by a few minutes. I guess next time I will just complete an extra trip or two to make sure I get the guarantee for sure.