After setting any Layout, on deleting that Layout, Last selected layout name not appears in Layout-dropdown window but still appearing in Layout header. Refer attached video.

Reproduction steps:
1. Create a new project.
2. 'Layout' window > Select any Layout > For ex: Tall
3. Layout window > Delete Layout > Delete selected Layout
4. Observe 'Layout-header' name and 'Layout-dropdown' window.

Actual result:
Last selected layout name still appearing in 'Layout-header' even after deleting it from 'Layout-dropdown' tray.

Expected result:
On deleting the last selected Layout, its name should vanish from 'Layout-header'.

Occurring on: 2021.2.0a1, 2021.1.0b2, 2021.1.0a1

Woring fine: 2020.2.2f1, 2020.1.17f1, 2019.4.16f1

Environment: Windows 10 and Mac 10.15