Problem

Let's imagine we have a segment containing 3 tags <1><2/></1>
If we delete tag <1> - </1> is deleted automatically so both <1> and </1> are deleted
Now if we try to delete <2> it becomes before <1> instead of beeing between tags <1> and </1>
See screenshot for details (1 and 2)

Solution

Find the cause and fix the issue