Mapping an existing item with a new index number

In almost every testcase I have one of the following warnings popUps after running the executeplan

The namemapping situation before running:

After running:

Why does the system want's to mapp an existing item with a higher index number ?

When I accept the Intelligent Fix (what I usually don't do), the next time I run the testcase then can happen 2 things:

1) The system indicates that the Index Mapping value = 5 and the Found index = 4 or
2) The system indicates that the Index Mapping value = 5 and the Found index = 6

How can I prevent this ? I just want to keep the first mapped item and wan'tt no warnings in my logging

Greetings,

Sjef