"My 1098-T box 1 is Blank for 2019, but the tuition for spring 2019 was included in 2018 1098-T box 1, and I claimed in last year. So I think I should not claim it this year again, right?"
That is right. If Spring 2019 tuition, was actually paid for in 2018; it should be claimed on the 2018 return and not on the 2019 return.
