'Run through Filters' NOT working

'Run through Filters' NOT working

Hi,

I have hundreds of emails I've migrated from Google Apps in my inbox. I've created a filter that matches the 'TO' field that contains a specific address and applies a label. When I check the filter and click 'Run through Filters', then select the Inbox folder, everything seemingly works. A success message is displayed. HOWEVER, no email in my inbox gets labelled at all.

Why is this not working?

Thanks
Lukas