I don’t know if OGS recalculates your rating between games.
Since the termination-api gives one entry with your initial rating, but no other entries independent of finished games (or outcome -1), I don’t think, that recalculations happen in between.
What I’ve observed is, that the rating shown on the Home page is cached. It doesn’t get updated after you ended a game. You have to close the tab or restart your browser to get it updated.
Please note that I don’t know how the OGS backend works and I cannot look at its code. Neither I had a look at the open source part of OGS.
I gained the knowledge of the OGS rating system by reading the introduction post of it in this forum OGS has a new Glicko-2 based rating system! [2017] and the implementation guidelines of the inventor of Glicko2 http://glicko.net/glicko/glicko2.pdf
With this information I’ve written a script that can reproduce ratings similar to the ones in the termination-api.
(I’m able to reproduce ratings within a small error margin to the OGS ones). I still don’t know everything about how OGS Glicko implementation works.