Issue Summary

Unable to search filter with 3+ multibyte characters.

Steps to Reproduce

1. Create a filter named 'マルチバイトフィルター'
2. Navigate through [Settings] > [System] > [Filters]
3. Search filter with 'マルチ'

Expected Results

The filter created in step 1 will show up.

Actual Results

The filter created in step 1 won't show up.

Workaround

Two or less chars work as expected. In the sample above, searching by "マル" will work.