With Android Lollipop rollouts slowing down, there are still a few stragglers out there waiting for OTA updates from various U.S. carriers to Android 5.0 Lollipop. Among them, Asus's ZenFone lineup, including the ZenFone 4, ZenFone 5 and ZenFone 6 smartphones, which just announced a delay in its OTA rollout for Android L.

That's right, if you own an Asus ZenFone 4, 5, or 6 released in 2014, you probably won't have the final update to Android 5.0 Lollipop for a little while. Officially, the ZenFone line was supposed to get Android L in "mid of May [sic]," according to Asus's announcement on its customer forum (via GSMArena). But that's been pushed back after the company has struggled to implement the update due to "verification issues."

The PadFone S is also included in the official postponement, along with the Asus Padfone Infinity 2, the second of which is indefinitely postponed.

So far, the Asus ZenFone 5 LTE has been the only device from the current line that has gotten a firmware update to Android Lollipop, but that device also has a downgrade to KitKat available due to Asus's Lollipop issues. That update brought standard Android 5.0 Lollipop, along with a few Asus custom properties, like Webstorage, auto-start Service Manager, and Super Note.

Asus said it was "currently working on the related issues" and will "release the upgrade as soon as possible." It's all around bad news, for Asus users, and for an Android OEM that, when it's not collaborating with Google, is still quite a market underdog.