Fieldset Modal Sidebar Scroll is not working properly

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.4.1 CE GA2, 7.4.2 CE GA3, 7.4.13 DXP GA1, Master
• Component/s: Data Engine
• Labels:
  • soy_removal_in_forms
• Fix Priority: 4
• Sprint: Forms_7.4_16
• Git Pull Request: https://github.com/liferay-forms/liferay-portal/pull/258

Description
The scrolling of the sidebar on the Fieldset Modal is not working properly. It's not possible to see the field you're editing on the sidebar when the fields on the builder require a scrolling.

Steps to Reproduce

1. Go to Content and Data > Web Content > Structure > Fieldset tab
2. Add some fields until the scroll bar appears
3. Scroll to the last field and observe the sidebar (bug)

Expected Result
Sidebar should scroll together with the fields.

Actual Result
The sidebar is not scrolled together when scrolling the builder (ActualResult_May12_LPS-132125.mp4)

Reproduced In
Master: 6bcd6f83bd8bcc185830b6d87d267a217df3c2e1