How does the new QQ restore the cover to the default? I added one. Why can't it be deleted?

Take the mobile QQ V8.3.9 version as an example, and the operation method is as follows:

First, open mobile QQ, enter my profile page, and click More in the upper right corner.

Secondly, in the pop-up options, click Information Card Settings.

Third, click on the cover.

Four, in the custom cover, you can choose a recommended cover, and then click the Settings button below.

5. Then go back to the custom cover, find the cover you just set, and click the Cancel button below.

Six, back to my profile page, you can see the cover back to the default.