Hello Bartlomiej,
Thanks for your question.
Please note that
RadComboBox control has its
AutoSize property set to
true by default. That said, this control automatically determines its size based on its contents. This causes the anchoring mechanism to fail since the control cannot be resized.
My advice is to try setting
AutoSize property of the control to
false and after that set its
Anchor property.
I hope this helps. You can write back anytime you need further assistance.
Best wishes,
Deyan
the Telerik team