Steps to Reproduce

1. run zk-5374.zul in ZK-5374
2. check accessibility with Chrome Lighthouse 10.0.1

Current Result

Failing element:
Name Description Item 1 Item 1 description Item 2 Item 2 description ...
<div id="z_2" class="z-tree" tabindex="0" role="treegrid">

focus
<button style="top:0px;left:0px" id="z_2-a" onclick="return false;" href="javascript:;" class="z-focus-a" aria-labelledby="z_2" aria-label="focus">

Expected Result

no error