The game that is "autoloaded" at the start of the game is not the last game you played, but the first game that was ever autosaved. Games that are autosaved in the future will never be autoloaded, only the originally-autosaved game will be.  Basically the autosave feature only works "once", after which GNOME Chess will never open to a blank board; if the game ends, the history won't be properly updated and so the same file will be autoloaded again from the same point in the future. No way around this without deleting the cached PGN.

Furthermore the titlebar incorrectly displays the path to the autosaved PGN as if the PGN had been opened manually; when a file is autoloaded the titlebar should just say "Chess".  This is all broken since v3.6.1; it was fine in the v3.4 branch.

I'll attach a proposed patch for these issues.  I also found a bug where the game was not autosaved if it was manually loaded from a PGN (probably put in place to not override the original PGN, but it should still be autosaved!); that's included in this patch since it affects the same lines of code.