Preview does not work for some icons

[mig-sam]

Environment

Jmix version: 2.8.999-SNAPSHOT
Jmix Studio Plugin Version: 2.8.0-253
IntelliJ version: IntelliJ IDEA 2025.3.3

Bug Description

Preview does not work for some icons

Steps To Reproduce

1.Add buttons to descriptor:

 <button id="btn" text="Btn" icon="ANCHOR"/>
 <button id="btn2" text="Btn2" icon="ADD_ACTION"/>

2.Launch preview

Current Behavior

Icon is shown only for one button

Expected Behavior

Icons are shown for both buttons

Sample Project