Fortnite” on Android is reportedly experiencing some performance issues, according to a tweet from developer Epic Games on Tuesday.

“We have seen reports that some players on 4GB Android devices are encountering an issue causing poor performance,” Epic said. “This is due to multiple background applications running — leaving the device without enough memory for ‘Fortnite.’ We are investigating and working on a fix!”

The Android beta is currently available on select Samsung devices only. Epic Games president Tim Sweeney unveiled it during Samsung’s Galaxy Unpacked 2018 event on Aug. 9. Samsung’s latest flagship smartphone, the Galaxy Note 9, also debuted during the event.

“Fortnite” on Android is currently compatible with following devices: Samsung Galaxy: S7 / S7 Edge , S8 / S8+, S9 / S9+, Note 8, Note 9, Tab S3, Tab S4. It will launch on a wider range of Android phones and tablets in the near future. In a recent interview with Variety, Sweeney said “Fortnite” has the potential to reach a “modest” 250 million players when it does so.

“Our expectations for 2018 are modest because ‘Fortnite’ requires a recent high-end Android smartphone,” he said. “‘Fortnite’ brings the game’s full PC and console experience to Android; of the roughly 2.5 billion Android devices, we estimate around 250 million are Fortnite-ready.”

Ars Technica recently got some hands-on time with the beta and called its performance “surprisingly sloppy.”

“Having only one compatible Samsung device, we can’t comprehensively speak to how well ‘Fortnite’ works on other Samsung phones, but our in-house Galaxy S8+ couldn’t get anywhere near 30fps performance without dropping to its ‘low’ visual preset, which summarily does the following: drops the resolution to somewhere around 480p, removes all traces of anti-aliasing, drops texture resolution, simplifies all in-game geometry, and removes all shadows,” it said.

Variety reached out to Epic Games about its Android woes, but the developer said it doesn’t have more information to share at this time. It didn’t provide an ETA on a fix.