Sorry for the slow reply, I've been without internet for a few days.
While the issue persists no XP is gained from any action whatsoever. Any XP gained on a run without the bug present is retained when relogging into a world just fine, however, when the bug is present any actions that would provide XP don't seem to contribute to the overall gain following a relog. This bug only seems to manifest upon the initial start of a game, regardless of whether the world is new or old. And even then it's random, it either works or it doesn't. I haven't seen it appear mid-game at any point.