Deed/book conversion gave xp. Underspire boss battles give xp, Underspire treasure chests give xp for the current kingdom. Event tiers give xp as well. And of course chrystal offers give xp. On top of kingdom tasks. Not all of them are big numbers. Some are smaller than others. So definitely not a bug at this point.
So, the TLDR to this is:
Because of the existing data around Broken Kingdom unlocking as the first Kingdom, which differs from all the other Kingdoms, it starts with 212 XP.
Trying to change this so Broken Spire didn’t start with any XP was deemed a risk, so it was left unchanged when we updated the Kingdom levelling system.
Not a bug in the sense that it was intentionally left as is and so far, won’t be changed in future.
Feels like a bug because it is the only Kingdom that gives you starting XP.