If a spell can be upgraded the upgrade button blinks, but not with Ajax’s spells.
Could you please let us know on which device and OS version do you play?
For me they blink properly if I don’t have a currently running upgrade for a power.
Android 7.0, newest Version Device LG G5
I noticed the same thing. iOS, the 2.92 update. All the other powers eligible for upgrade blink, Ajax’s don’t.