SpriterHaxeEngine. Unserialization issue

I have updated haxe and haxelibs to the most recent versions and face an incomprehensible problem.

On cpp (android) at the stage of package unserialization my app crashes with the following exception:

Called from haxe.Unserializer::unserializeObject /usr/local/lib/haxe/std/haxe/Unserializer.hx line 205
Called from Reflect::setField /usr/local/lib/haxe/std/cpp/_std/Reflect.hx line 41
Exception: Invalid field:_inPool

The data from the SCML pack file is read correctly:

o : SpatialInfo
k : _inPool
v : false

Attempts to solve the problem on my own were unsuccessful. Please help.

It seems that only dynamic types allow this

After researching, I figured out what the problem was. I set the default value for _inPool in constructor and only after that Reflect recognized this field.

This way of declaring didn’t work:
Снимок экрана 2021-07-05 в 11.09.49

Tell me, is this normal behavior? Why did it work with haxe 3.x? Or is this a bug?