Version

4.6.0

Reproduction link

https://www.echartsjs.com/examples/en/editor.html?c=bar-animation-delay

Steps to reproduce

1. Visit the example page.

2. Click on the 'Stack' icon to change the bar chart from tile view to stack view.

3. Hover on the other icons on the toolbox, say 'save as image'.

4. The title is [object Object] instead of 'Save as Image'.

What is expected?

The title of the toolbox icons should remain text value.

What is actually happening?

They are changed to [object Object]