If you own an AT&T variant of the first-gen Moto X smartphone that is the XT1058 model, then you're in for some bad news.

The U.S. carrier has suspended the Android 5.1 Lollipop update for the Moto X 2013. The carrier broke the news on its support forum that the software update will be halted temporarily from Monday, July 20.

AT&T, however, did not give any reason as to why the over-the-air (OTA) software update which was downloadable only on Wi-Fi was being suspended.

"Effective July 20, 2015, the Android 5.1 (Lollipop) software update for the Moto X (XT1058) has been temporarily suspended. We apologize for any inconvenience and are working to resolve this issue as quickly as possible," revealed the AT&T support page.

Earlier on July 7, AT&T pushed out the Android 5.1 Lollipop update to the Moto X 2013, which was set to bring several enhancements and new features users' way. The update meant that AT&T Moto X 2013 users would see a jump from Android 4.4.4 KitKat to Lollipop.

Motorola's David Schuster, Senior Director of Software Product Management, also confirmed the update's status in a Google Plus post.

Earlier in June this year, as we reported, Motorola started pushing out the Android 5.1 Lollipop update for the first-gen Moto X, but the software update was only meant for the unlocked retail variant of the devices in the U.S.

However, at the time Schuster had let on that a soak test for the Moto X experienced hiccups and the company had addressed the issue. A possibility exists that the Android 5.1 Lollipop update to the AT&T variant of the Moto X 2013 encountered some bugs, which is why the network operator has opted to abruptly pull the Wi-Fi-only update.

Since the Moto X 2013 jumped straight to Android 5.1 Lollipop from Android 4.4.4 KitKat, it likely encountered some bugs.

Alternately, AT&T could be encountering other issues such as skewed logistics for the roll out or other situations, which do not directly relate to the update's quality.

AT&T is working on resolving the issue but it is not known when the software update will resume its variant of the Moto X 2013.