Answer by Elijah Lynn for Gmail's label and skip the inbox filter

If you are getting the label added then that confirms that the filter is being applied, and then if most messages skip the inbox but only a few make it to the inbox then it is likely that Gmail is overriding your filter.

There is hidden setting under Settings > Inbox > Filter mail with two settings:* Override filters - Include important messages in the inbox that may have been filtered out. (default)* Don't override filters

Choose "Don't override filters".

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source: https://www.theinternetpatrol.com/gmail-skip-the-inbox-filter-not-working-this-may-be-why-and-how-to-fix-it/