You should always plot a graph when doing any solving type activity. Some of your equations have two solutions as I alluded to before. When you use find root you will get one of them and this may not be the same one excel gets. Use solve to get both. Sometimes you can also get multiple solutions if you have alternating cash flows and most introductory finance texts note this as one of the drawbacks of internal rate of return.

Solve[TimeValue[Cashflow[values[[1 ;; 7]]], r, 0] == 0, Reals]

{{r -> -1.25357}, {r -> -0.724255}}

Check both of your answers.

TimeValue[Cashflow[values[[1 ;; 6 + 1]]], r, 0] /. {r -> -1.2535683433939733`}

TimeValue[Cashflow[values[[1 ;; 6 + 1]]], r,  0] /. {r -> -0.7242552925326607`}

Plot the NPV. There are two solutions for some of the NPV curves.

NPV[i1_] := TimeValue[Cashflow[values[[1 ;; i1 + 1]]], r, 0];
curves = Map[NPV[#] &, Range[1, 6]];
Plot[curves, {r, -1.5, 0.3}, 
 PlotRange -> {{-1.5, -0.3}, {-100000000000, 100000000000}}]

All your internal rates of return are negative. Mathematically speaking, Mathematica is giving you the correct solutions. In fact it even gives you multiple solutions. Unless you are a central banker these negatives rates don't really make sense even in the current deflationary environment so you might want to constrain your solutions

Solve[TimeValue[Cashflow[values], r, 0] == 0 && r > 0, r, Reals]

If you use your first 11 cash flows you gets solutions of -144% and -51% and if you plot the present value it approaches infinity as r approaches -100%. I guess if your current holdings are to become worthless in the next period then promise of $1 at that time would sound quite attractive.

IRR - Internal Rate Of Return ??

The main problem you are having is financial because the cash flows don't cover the initial outlay. Your initial negative cash flow is far too large and you need to remove three zeros before you will get any sensible answer. Evaluate the following to see whether your deal makes sense.

pv1 = TimeValue[Cashflow[values], r, 0];
Plot[pv1, {r, 0, 0.3}]

Also, I would avoid using Do and Print and instead create a function and then use Table to get your different IRR's.

irr3[i1_] :=  FindRoot[TimeValue[Cashflow[values2[[1 ;; i1 + 1]]], r, 0] == 0, {r, .05}];
Table[{i, irr3[i]}, {i, 1, 30}]