Fall flat

The prop comedy in Las Vegas fell flat.

Source: wiktionary

When Sir Walter Scott, with a view to profit rather than fame, published "Paul's Letters to his Kinsfolk," with some very indifferent verses to celebrate the battle of Waterloo, Erskine, sitting at table, came out with the following impromptu:—

Source: wiktionary

And though [Terry] Border's overly punny captions fall flat for me, the images themselves exude enough delight to make it all a treat.

Source: wiktionary

United were made to pay for letting an eight-point lead as little as five weeks ago slip and, despite their final-day efforts, they will look back on a season where, when they needed to step up, they fell flat.

Source: wiktionary