Samsung is delaying the release of its first foldable smartphone, the Galaxy Fold, according to The Verge.

The Wall Street Journal reports that Samsung won’t release the Galaxy Fold until “at least next month” due to issues with review units that technology reporters have revealed. A string of reviewers found problems with the display, with it failing for a number of reasons.

Samsung was originally planning to release the Galaxy Fold on Friday, April 26, and the company has already postponed launch events in China.