The problem is that inside your UserForm you are only trapping the
events of a single instance of your class. This declaration:

Private WithEvents myCls As Class1

was used over and over in a loop in the UserForm_Initialize event to assign
each textbox to an instance of your custom class and then add each instance
of that class to a collection.

   The only reason this works at all is that at the end of the
UserForm_Initialize loop the myCls variable is left assigned to whatever the
last class you created was. If you have two textboxes on your UserForm this
will be TextBox2. Add more textboxes and it will be whatever one is last in
the initialize loop.

   The method you are using here allows you to *trap* events and respond to
them using multiple instances of a single class module. However, once you
start raising custom events from inside a class module, you must have a
separate object variable for each instance of the class whose custom events
you want to respond to in some other class, in this case your UserForm
module.

   There's no way to create a single event procedure in your UserForm to
respond to all the events for all your custom class instances. You'll need
to declare one WithEvents Class1 variable for each textbox on your UserForm
and create an F1Pressed event procedure for each.