Aircraft maker Boeing, already struggling to make its 737 Max fleet airworthy again, has reported issues with another one of the planes it produces.

Seattle TV station KCPQ says Boeing's 777X failed a recent safety test. The test, which bent the wings while the plane was still on the ground, reportedly resulted in the rear cabin depressurizing. A door apparently popped open, as well.

Boeing says the test for the plane, which is still in development, bent the wings "to a level far beyond anything expected in commercial service."

The plane's delivery to various air carriers had already been delayed because of issues with its engines, KCPQ says.

Meanwhile, Boeing has seen orders for new planes plummet compared to 2018. That follows the grounding of the 737 Max in March. The move came after two fatal crashes mere weeks apart.

The grounding has hit Southwest particularly hard. The airline owns more 737 Max aircraft than any other U.S. carrier.

The federal government hasn't said when the 737 Max might be able to once again carry passengers.