Iron-Icons not visible 21.0.0-beta1 on Vaadin 21.0.8 (production mode)

[osenbg]

Hello,

the menu Iron-Icons are not visible in Version 21.0.0-beta1.

Perhaps this helps.

https://stackoverflow.com/questions/68348596/the-iron-icon-not-visible-with-a-master-detail-view-generate-with-vaadin-app-sta