Turns out, not a bug, just a couple of misunderstandings.
SOLVED
Platform, device version and operating system:
Windows 7 x64, Steam
What you were expecting to happen, and what actually happened:
Changed class from Dragonguard to Bard approx 8pm AEST (or possibly about 1pm, if my memory fails me). Tried to change from Bard to Titan around 5:45pm AEST, but there’s a Change Cost of 50 gems. Restarted game, still the same issue at 6:05pm AEST.
I expected the class change to be free because it’s a new game day.
How often does this happen? When did it begin happening?
Every time I’ve tried this game day.
Steps to make it happen again
See above.
I expected a free class change every game day. Is it actually locked to 24 hours since the last change? If so, there definitely should be a count-down timer. I also expected a second free change for the Oracle class event, but I’m not getting that either (ie: same problem if I try to change class through the Oracle Event team builder).