The "Effect Controls" panel disappears randomly during editing and reappears in a new tab.

Issue
Clicking the "fx" toggle button on a clip causes the Effect Controls panel to turn black and reopen in a new tab.

Steps to reproduce

1. Open a Premiere Pro project with clips containing applied effects

2. Select a clip on the timeline with effects applied

3. Verify that the "Effect Controls" panel is open and visible

4. Click the small "fx" toggle button on the clip (to disable/enable effects)

5. The Effect Controls panel turns black/becomes unresponsive

6. The panel closes and reappears in a new tab instead of returning to its original position

Expected result
Clicking the "fx" toggle button should only disable/enable the effects on the clip. The Effect Controls panel should remain visible and functional in its original position.

Actual result
Clicking the "fx" button causes the Effect Controls panel to turn black, close, and reopen as a new tab. The panel becomes unusable until it's manually closed and reopened.

Screen recording

Adobe Premiere Pro version
26.0 build 72

Operating system
macOS 26.1 (25B78) on Mac Studio M1 Ultra

Video format
[Specify if applicable]

Comparative information

• Does it affect all projects or only some projects? All projects

• Does it affect new projects? Yes

• When did the problem begin? After installing v26.0 (January 25, 2026)