I'm playing in the windows version, it didn't happen only with busk, the problem also happened with the initial rock type monster, the crystal element monster that evolves at level 20 and the water type monster that evolves at level 18 (sorry I don't remember the names of the monsters), the only one I didn't have that problem with is the other rock type. Regarding what the evolution is canceled automatically, I mean that the evolutionary screen does not appear directly after going up to the required level if the level is reached after defeating the last enemy monster alive (I say this because the screen appears to improve some ability or statistics such as strength or resistance for example). although after the next fight they evolve