saved_change_to_* return `nil` in after callbacks in Rails 5.2

[tikh]

Looks like it's impossible to detect the previous value of a property in the after callback in Rails 5.2.

I have a simple model:

class Profile < ApplicationRecord
  typed_store :properties do |p|
    p.string :phone
  end

  after_save :debug
  def debug
    puts "saved_change_to_phone #{saved_change_to_phone.inspect}"
  end
end

p = Profile.create(phone: "123")
p.save
p = Profile.last
p.phone = "456"
p.save

# Displays:
# saved_change_to_phone nil