If you are unable to find an answer to your question — you may always ask it.
To change patterns:
If too many elements are removed user may:
Disable shields one by one to identify which shield causes elements removal.
Order of shields on the list mostly resembles their strength — with block shield the strongest.
If problem remains pattern adjustment is recommended to reduce number of false positives.
Limiting pattern scope can reduce detection sensivity — number of false positives, but also positives.