New Issue View "content" panel contains redundant vertical scrollbar on IE 11 and MS Edge

Summary

Environment

• IE 11
• MS Edge

Steps to Reproduce

1. Create a Connect add-on that displays panel on the left side of the issue page (either old-style panel or new "Content" panel)
2. Visit the New Issue View popup/dialog from Agile board

Expected Results

Content panel displayed without a redundant vertical scrollbar

Actual Results

Notes

• the problem affects other apps (it is not limited to our Issue Checklist app)
• the problem affects both types of apps that manually handle panel height through AP.resize and those that use Connect automated resize through "ac-content" attribute
• the problem affects only MS browsers (confirmed on IE11 and Edge)
• the problem does not occur on full/old Issue View
• the problem does not disappear if I resize the panel with AP.resize to a height much above the content height.