🐞 Adobe InDesign Bug Report — CC Libraries Panel Flickering on External Monitor (macOS Tahoe)
Product: Adobe InDesign
Version: 2026 (26.3.1)
Operating System: macOS Tahoe 26.3.1
Hardware: MacBook Pro M4
Displays: External monitor + built‑in laptop display
Panel Affected: CC Libraries panel
Reproducibility: 100%
Severity: High (UI flicker makes the panel difficult or unpleasant to use)

Summary of the Issue
The CC Libraries panel flickers continuously when InDesign 2026 (26.3.1) is used on a MacBook Pro M4 connected to an external display. The flicker is limited to the panel UI itself and does not affect other panels or the document area.
The flickering completely stops under two conditions:

When the CC Libraries panel is moved to the MacBook’s built‑in display.

This mirrors known InDesign UI bugs where panel or submenu rendering breaks only on external monitors. [community.adobe.com]

When the user backs out of or exits the specific Library being viewed inside the CC Libraries panel.

External monitors have been associated with flicker and UI redraw failures in InDesign, often independent of document content. [community.adobe.com]

The issue persists across multiple documents, including brand-new ones, indicating this is panel-level behavior, not file corruption.

Steps to Reproduce

Open Adobe InDesign 2026 (26.3.1) on macOS Tahoe 26.3.1.
Connect an external display to the MacBook Pro M4.
Open the CC Libraries panel.
Navigate into an existing Library containing assets.
View the panel on the external monitor.

Observed Behavior

The bottom portion (or the entire contents) of the CC Libraries panel flickers repeatedly.
The flicker occurs even when InDesign is idle (not interacting with the panel).
The flicker continues across all open documents and persists after restarts.

Expected Behavior

The CC Libraries panel should render normally on all attached displays without flickering or redraw failures.

Workarounds Found

Collapsing the CC Libraries panel stops the flickering immediately.

Dragging the panel onto the MacBook’s built-in display stops the flicker completely.

This behavior is similar to past InDesign external‑monitor flicker issues documented by Adobe. [community.adobe.com]

Backing out of the active Library being viewed also stops the flicker.

These workarounds confirm the issue is tied to panel content rendering + external monitor GPU/UI pipeline, consistent with known external‑monitor flickering behaviors previously reported in InDesign. [community.adobe.com]

Additional Notes

GPU Performance toggling (on/off) does not resolve the issue, though enabling GPU was suggested as a workaround for similar InDesign flicker behaviors in older versions. [indesign.u...rvoice.com]
The problem does not appear related to rulers or overprint preview (prior known flicker triggers).
Appears to be a new UI repaint issue introduced in the 2026 build.