Goofs

Several scenes have been flipped in edit rather than re-shot so characters are mirroring each other in frame... but with no thought to U.S. insignia and text on crates, etc being backwards.

At 18:00, where the Chaumont American HQ, stands, there is a cactus in the left foreground and a plan tree to the left of the stone tower. There is no such vegetation in Northern France.

You talk about the 'premiere' being in Nov 2019 but then state the film was released in April 2019? Also WW1 ended in Nov 1918 not 1919.

There was only an Armistice in November 1919. The Treaty of Versailles peace document was signed in 1919 and ratified in 1920. The usage "1918-19" is a common one for the period of the war,

The gas-mask container should be worn on the chest, not on the belly. Several US soldiers, most notably Captain Rivers, make this mistake. Also, the Sam Browne belts of General Pershing and Colonel Morrison are worn too low, and the brace should pass under the right shoulder-strap, not sit between it and the collar.

At 12:10 Captain Rivers tells his men to wait for the barrel to be changed. He is referring to machine gunner to change the barrel on the weapon in order to continue firing. This is a feature of air-cooled machine guns which have be used since 1939. WWI-era machine guns were water-cooled, which are shown, which allowed the gunners to shoot for a much longer time.