Can't access protected property with Reflection

While debugging at a break point, I'm unable to access the property Rectangle_1 (and other sibling properties), using Reflection, that are visible in a watch window.

In the Immediate Window, If I try

typeof(LoadRecipeSlots).GetProperty("Rectangle_1")

the result is null.

but if I try

typeof(LoadRecipeSlots).GetProperty("Visible")

the result is

{Boolean Visible}
Attributes: None
CanRead: true
CanWrite: true
CustomAttributes: Count = 1
DeclaringType: DeclaredProperties = {System.Reflection.PropertyInfo[65]}
GetMethod: {Boolean get_Visible()}
IsSpecialName: false
MemberType: Property
MetadataToken: 385877353
Module: {ControlsCF.dll}
Name: "Visible"
PropertyType: DeclaredProperties = {System.Reflection.PropertyInfo[0]}
ReflectedType: DeclaredProperties = {System.Reflection.PropertyInfo[7]}
SetMethod: {Void set_Visible(Boolean)}

The property Visible seems to be a property of a parent class.

The property Rectancle_1 is protected in LoadRecipeSlots and I'm trying to use Reflection to access it from a partial class of the same name, which I'm unable to do. The property is however accessible as code in this partial class.

Most of the code is autogenerated by the tool in use, iX Developer, so I'm not able to create a concise example. If something is missing, let me know, and I'll try to add it to the question.