Minecraft Bedrock release 1.13.0 and 1.13.1: Custom player's controller_animation cannot always run a designated /function command most of the times.
For an unknown reason as well, MCPE-56119 is also (may be) related with this problem.
An attached version of my prototype add-on will confirm this happens, specially on mobile. No incorrect or typos where found, its just that the game does not run them properly.
Maybe the following reasons:
Insufficient memory. Unable to run multiple commands – proceeding with no commands?
World Overload. A lot of commands is already running into your world or the game cannot handle both chunk loading and commands at the same time?
Character Creator. With the new Character Creator introduced, you (developers) may have made some changes to the animation_controllers that result in such a problem, since anyway, Character Creator involves 3D models for players and animations. Plus, this problem didn't exist before it was introduced!
Related animation controllers issue that may be because of the same problem
https://bugs.mojang.com/browse/MCPE-54259
@Urielsalis fixed