I bought a popcorn bowl that turned out to be terrible. It came with a leaflet coupon saying if I left a 5-star review, they would send me another bowl for free.

The comment I tried to leave was a short, fair, polite statement along the lines of 'this bowl doesn’t meet the claims X and Y on the description, and came with an offer to trade a good review for another bowl for free." That review got flagged by the automod and was ultimately rejected. If I recall, the rejection message wasn’t even specific on what rule my review broke.