Continuity mistake: When Doctor Strange attempts to use the Time Stone on Ebony Maw, Maw ties up Strange telepathically and strangles him unconscious. Beside Strange is a police car and a motorbike tipped on its side. Maw then lifts the ground he is lying on, but the police car has been replaced by an SUV and the motorbike has disappeared. The shadows also change. (00:23:25)
Continuity mistake: When Groot creates a handle for the axe with his arm, he chops off the arm and it lands on the ground. The sharp end is facing to the right when it lands, but when it begins to lift, the sharp end is now facing to the left. (01:44:20)
Suggested correction: Looking at the screen, sharp end is to the right, Groot adds the handle as he does he rotates it, and then when he creates the handle, Stormbreaker falls as expected.
You're talking about the wrong part of the scene. The mistake occurs after Groot adds the handle and cuts off his arm. After the completed Stormbreaker falls, its position changes when the camera cuts to it starting to rise.
Continuity mistake: In New York after Bruce tries to become Hulk, in one shot there's a minor mud stain on his shirt, then the angle changes and it's suddenly a massive brown splat. (00:22:15)
Revealing mistake: Just after Proxima Midnight and Corvus Glaive land in the train station, there is a wide shot where they begin approaching Wanda and Vision. In the wide shot, their shadows do not appear to match up with each other, despite being under the same lighting. Proxima Midnight's shadow is positioned in front of her and is quite heavy, but Corvus Glaive's shadow is positioned more to his left and is much lighter than Proxima's. (00:40:20)
Continuity mistake: When Peter sees the ship whilst he is on the school bus, he taps Ned on the shoulder and asks him to make a distraction. When he taps Ned on the shoulder, Ned has earphones in both ears, and one of the earphones falls out when Peter taps him, whilst the other earphone remains in his ear. But in the next shot, neither of his ears has an earphone in them. (00:18:25)
Continuity mistake: When Ebony Maw is walking past the dead Asgardians, the camera pans from feet up to his face, and Corvus Glaive is walking past him. The shot cuts to a different angle, where Corvus Glaive is now several meters away from him. (00:01:35)
Continuity mistake: Thor says "You talk too much" whilst Thanos has his hand grabbing Thor's head. Thanos' fingers are close together on one side, with his thumb holding the other side. Two shots after, when Thanos asks Loki for the Tesseract, Thanos' fingers are spread apart. Two shots after that, when Thanos says "Or your brother's head", his fingers are suddenly close together again. (00:02:55)
Continuity mistake: When Thor, Rocket and Groot begin charging towards the army after arriving in Wakanda, the shot from behind them shows Rocket and Groot running slightly behind Thor. Then it cuts directly to a shot in front of them, just before Thor jumps into the air, and Rocket and Groot are now further back. (01:45:50)
Trivia: Directors Joe and Anthony Russo like to put in nods to their previous works in their MCU films. In this movie, a man closely resembling Tobias Funke in his "Blue Man Group" makeup (from the series "Arrested Development") is briefly visible inside of one of the Collector's cages behind Gamora for a brief instant. It's hard to spot, but he's there.
Continuity mistake: Whilst they are discussing the plan on Titan, just after Star-Lord tells Tony to not call them plucky, the shot cuts to Tony turning his head to Star-Lord. In this shot, Tony and Star-Lord are positioned around 90° rotated from each other, but in the next shot, the two are suddenly facing each other directly. (01:22:55)
Continuity mistake: When Black Widow stabs Corvus Glaive, she kicks him to the ground and he drops his weapon, with the weapon landing beside him. Proxima Midnight then runs up to Black Widow and Captain America picks up Corvus Glaive's weapon, but it is now much further away from him. (00:41:05)
