ExpansionPanel in content projection in modal closes after first open

[ivanivanyuk1993axelot]

Reproduction

Use StackBlitz to reproduce your issue: https://stackblitz.com/edit/angular-pjv1un

Steps to reproduce:

1. Open modal
2. Close modal
3. Open modal

Expected Behavior

Expansion panel is opened

Actual Behavior

Expansion panel is closed(it has correct class, but style visibility: hidden, height: 0)

Environment

• Angular: ~8.2.0
• CDK/Material: ^8.2.0
• Browser(s): Chrome
• Operating System (e.g. Windows, macOS, Ubuntu): Ubuntu, Windows 10

[TheParad0X]

Same Problem here.