Routing 404s issues

I have some custom routes defined as follows. My issue is that IF the post doesn’t have a tag it returns a 404, and if I have a new tag created that isn’t part of the routes.yaml it also 404s.

routes:
  /signup/: members/signup
  /signin/: members/signin
  /account/: members/account
  /:
    data:
      post:
        resource: pages
        type: read
        slug: landing
    template:
      - custom-home
  /posts/:
    controller: channel
    template: index


collections:
  /announcements/:
    permalink: /announcements/{slug}/
    template: index
    filter: tag:announcements
  /gaming/:
    permalink: /gaming/{slug}/
    template: index
    filter: tag:gaming


taxonomies:
  tag: /tag/{slug}/
  author: /author/{slug}/

Is it possible to have custom routes for some tags, and everything else to still work via /{slug} path?

This is because posts have to belong to a collection to have the {slug} as URL.
In your case, anything that doesn’t have the announcements or gaming tag will not belong to a collection.

You could set up your routes in a different way, have the /posts/ as the collection without filter, and the /announcements/ & /gaming/ as channels.

See the topic below:

Yes, you need to keep the default collection with your other tags excluded, eg:

collections:
  /announcements/:
    permalink: /announcements/{slug}/
    template: index
    filter: tag:announcements
  /gaming/:
    permalink: /gaming/{slug}/
    template: index
    filter: tag:gaming
  /:
    permalink: /{slug}/
    template: index
    filter: tag:-[announcements,gaming]

Thank you @Kevin. That works great.