A Bug in campaign SotA in version 1.15.3

[bobpanda]

I run my wesnoth game on MacOSX 10.14.6.
Game version:1.15.3
Problem description: After Ardonna turns into a lich, all the necromancers are able to transform into liches. Every time I load the game the first time I start the game, all the liches are ready to advance to l4 ancient liches. However, if I load a save file again without restarting the game, these l3 liches can only get AMLA of +3 max HP instead of leveling into l4. Moreover, this problem can make replays crash(I remember it is the out-of-sync error or something like that). So I have to restart the game as a refresh to deal with this problem.
P.S. I can provide screenshots of such problem, but I don't know how to post pictures in the forum.

[SigurdFireDragon]

That looks to be this bug:
https://github.com/wesnoth/wesnoth/issues/4402