Hi crumou

Seen you do this couple of times: When 1 area like here a scrub zone, shares the outline of a larger area, it has to be mapped as outside without any inner/outer role to in this case the wood. In this case I've split the scrub and wood and made each a simple polygon. See https://www.openstreetmap.org/changeset/134331066 for the change

If you need clarification, feel free to ask or revisit the multipolygon wiki which details what's outer and inner, special attention for multiple inside areas that form a single inner zone requiring a separate 'inner' outlines which enclose these.

ciao