What gameplay feature is this bug affecting?
Energy

What's the issue? Please include any error messages you receive and as much detail as possible.
I had saved up my level-up for the rollover so I could explore nearly 3 full energy bars - first from just waiting, second from the level-up and third the daily energy boost. But after I leveled-up and used up all my energy I realized that the energy boost button was gone. The level-up ate my daily boost.

Any links relating to this bug? For example, if a particular lion is bugging, what is the link to that lion?
uh, my king I guess: https://www.lioden.com/lion.php?mid=438268

Any screenshots you can provide us with?
I *could* take a screenshot of an empty energy bar and no energy boost button above it but that's more effort than needed /lh

Please provide us with step by step explanation how this bug happened so we can attempt to replicate it. If it's complex, please include screenshots where possible:
After rollover I sent some hungry NCLs to the nature reserve, sparred with my submale and sorted out my food before going to explore. I explored in the Tropical Forest until 0 energy, leveled my king up to level 11 and continued exploring - this time in the Dry Savannah. Afterwards I noticed my energy boost was gone when it was still there before the level-up.