Wait, what just happened? Yesterday I sold all my shares in company (bought at 1.5) and it says I earned 400+. Then I rebuy later in the evening @ 1.57.

Now my portfolio says my realised profit is 260+, but my average share purchase price is 1.522, but with "profit" of 117? What the hell???

I believe the average share price is calculated based on all the shares bought (including those that you have sold). That's what Rakuten has been doing to my stocks. I don't like this style but that's how Rakuten calculates