Increase document limit/sample size in Discover?

How do I overcome the "Document count is based on smaller..."-limitation in Kibana's Discover (without Dashboard)?

It seems to have a hard limit on 5000 documents taken into account.

(My date range is set to max; there are > 400.000 documents in the index; discover:sampleSize does seem to only affect the number of entries visible in the table)

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