Foldable phones are once again facing questions about their durability.
The Galaxy Z Flip and the Motorola Razr are now both available to buy in the US - but early reports suggest the screens are easily damaged.
三星Galaxy Z Flip手机和摩托罗拉Razr手机目前在美国均有售，但是早期报告指出，这两款手机的屏幕都很容易损坏。
One outlet published photos of two layers of the Razr's display separating, affecting the touch screen.
The Galaxy Z flip, meanwhile, boasts a "flexible glass" display - but tests appear to show it scratching as easily as plastic.
与此同时，三星Galaxy Z Flip手机据称拥有“柔性玻璃”显示屏，但是测试显示，这种“玻璃”和塑料一样容易留下刮痕。
It's not yet clear how widespread the issues might be.
In a statement, Samsung said the display had a protective layer, and had undergone extensive testing.
"While the display does bend, it should be handled with care," it said.
The Z Flip's "ultra thin glass" is one of Samsung's primary marketing messages for the new phone.
But a durability test conducted by popular YouTuber Zack Nelson suggested it was no more durable than a soft plastic screen - and could even be dented by a fingernail.
Nelson, who has more than 5m subscribers to his YouTube channel, where he regularly tests new tech, said Samsung's screen scratched "exactly how a plastic screen would react".
"I don't know what material this is, but Samsung definitely shouldn't be calling it glass," he said.
He found that the screen of the Motorola Razr scratched as easily but it is not marketed as "glass".
The Motorola Razr was released 13 days ago in the US, but a technology journalist for Input Mag says the flexible screen on his handset has already broken.
In a video released by the firm ahead of its launch, Motorola warned about screen "lumps and bumps", but said they were normal.
lump[lʌmp]: n. 块，块状；肿块
bump[bʌmp]: n. 肿块，隆起物
Raymond Wong, Input's reviews editor, said the upper layer of the Razr's screen separated from the bottom, creating "a giant horizontal air bubble" for no apparent reason.
He wrote that the fault appeared after a 45-minute train ride during which the phone was in his pocket.
When he took it out, "the screen was completely warped from hinge-to-hinge with the top layer raised like a poorly applied screen protector," he wrote.
But Mr Wong said that apart from the visual problem, the damage has affected the responsiveness of the touchscreen.
Motorola's parent company, Lenovo, said it was investigating.