Samsung’s $2,000 folding phones appear to be more delicate than Samsung claims and sample units were reported to break after some days of use.

Journalists who received the phones to review before the public launch said the Galaxy Fold screen started flickering and turning black before completely fizzling out. Two journalists said they removed a protective layer from the screens that they thought was supposed to come off. But CNBC reporter Todd Haselton claims that although he left that layer on, the screen of his Fold sample device still broke.

The Verge’s Dieter Bohn posted earlier on Wednesday that his sample phone appears to have a defective hinge with a “small bulge” that he can feel that’s causing the screen to “slightly distort.” Bloomberg’s Mark Gurman says his “review unit is completely broken just two days in,” but noted he accidentally removed a protective film on the screen.

Samsunghad warned on Wednesday not to remove the protective layer.

The Galaxy Fold is about the size of a standard smartphone when folded, but can open up to the size of a small tablet. The phone is designed to work whether closed or open, and Samsung is advertising that the phone's the screen can withstand being opened and closed 200,000 times, or 100 times a day for five years.

“We will thoroughly inspect these units ... to determine the cause of the matter,” Samsung said in a statement.

The Galaxy Fold goes on sale April 26 in the U.S. for $1,980.

Samsunf faced a disastrous rollout of a new phone in 2016 with the Galaxy Note 7, which Samsung eventually recalled because its batteries were catching on fire.