Bug: Experience gained by attacks on NPCs (possibly player cities as well, but only tested on NPCs) is not retained if the attack was launched before maintenance and the hero is still on return when maintenance happens.

How to test:

Notate hero experience points before the attack.

Send out a winning attack and notate the experience gained in both the report and in the hero detail view via the Feasting Hall.

Initiate server maintenance routines while the hero is still returning.

Notate the hero experience points after maintenance is complete. If the bug exists (which it does, and has for a very long time), the experience points will be back to the same as what they were before the attack.