[5.0.26] FixElementSize behavior errors when getting elements in the collapsed combo #6416

Describe the bug / 问题描述

Using fix-element-size behavior, then collapse the group which has "fixed" element, it will get the error below

And I found it will get each element from the ElementController in the fixNodeLike() When the group is collapsed, even though the nodeId is correct, but it still return undefined, see the code below https://github.com/antvis/G6/blob/0ab5f8d1a3c14cd9037841f766b687d5c0bf3217/packages/g6/src/behaviors/fix-element-size.ts#L218C25-L218C35

Reproduction link / 重现链接

No response

Steps to Reproduce the Bug or Issue / 重现步骤

No response

G6 Version / G6 版本

🆕 5.x

Operating System / 操作系统

macOS

Browser / 浏览器

Chrome, Edge

Additional context / 补充说明

No response