I have a data set with repeated measures for each individual. That is there a re two groups, treatment and control. And each individual is measured at 3 time points. But there are missing values. That is I don't have data for all 3 time points for all of the individuals. I carried out a SPSS GLM by Analyze->General Linear Model->Repeated measures
I have some difficulties in interpreting the output.
First I looked at the

As sphericity assumption is valid(non significant) I concluded that There isnít a significant difference between the means of variable1 at different time points for treatment and control groups.

Also by looking at the between subjects effect table I concluded that there isnít a significant difference of variable1 levels between treatment and control groups. Are my interpretations are correct?

But when I plotted the two groups over time I get this:
By looking at this I feel like the mean values of treatment group should show a difference over time and also there should be a difference of means between the two groups?
Is my interpretations from tables correct?
Why does it show on the plot like this and yet the results are non significant?