These are non-transitive extended communities. They can not cross an EBGP boundary, the deletion in policy-statement BGP_sanitize_in is perhaps superfluous.

Try the following, instead of 0, use 0.0.0.0

In T220669#5282795, @ayounsi wrote:

Once we're ready to drop invalids everywhere, move the above term to the BGP_community_actions policy.

To be researched: I'm not sure yet if bringing the validator closer to the routers (eg. in POPs) brings significant improvements. If so and once T96852 is solved, we could bring them closer to the POP routers.