Problem with adding signal

When user adds signals to some component, they are not shown on the list at first.

Steps to reproduce:

• go to Properties / Local Custom Properties
• add 2 different signals

Actual: signals are added in code but they are not visible in the list.

Expected:  signals are added in code and are visible on the list

More steps:

• add some other property, eg. bool or int
• remove this property

Actual: signals show up suddenly

Expected: signals should be visible all the time