I find this:
There are two solutions for t.3s.
You find none, maybe because in your solve block the labels of t.3 are different.
The guess value t.3 is labelled 'variable', while the t.3 in the constraint is labelled '-' (automatic).
Make them have the same label and see what happens.
For your R.2s solving, a similar thing happens. The labels for R2 are the same, but those of r1 aren't. Correct that and see what happens.