QTextCursor beginEditBlock and endEditBlock break layout when document contains QTextBlock is not visible.

When I use beginEditBlock and endEditBlock, layout breaks.

This occurs on a special condition.

In my document, there is a QTextTable at least.

And there is also some unvisible QTextBlocks.

The cursor operation is deletePreviousChar().(not insertText)

In my case, QTextTable and unvisibleQTextBlock and deletePreviousChar operation.