Metrics calculation uses replies that are no-longer valid because some of its parent has been cleared... this is the case for both option and list questions:
1) Option question
1.a) Answer with followup
1.a.1) Followup question
1.a.1.a) Answer of followup with metrics
When I answer 1.a) + 1.a.1.a), metrics from it are used. When I clear answer of 1), metrics from 1.a.1.a) are still used = expected would be not to use it anymore.
1) List question
1.a) Item of list
1.a.1) Question of list item
1.a.1.a) Answer of list item with metrics
When I create item 1.a) and select answer 1.a.1.a), metrics from it are used. When I delete item 1.a) metrics from 1.a.1.a) are still used = expected would be not to use it anymore.
This causes also weird-looking summary report (nothing answered but some metrics are there):