The Android 6.0 Marshmallow OTA update for HTC One M8 from 2014 and HTC One M9 from 2015 has been rolled out by other major carriers except for AT&T.

As it turns out, the Android 6.0 update for both One M9 and One M8 has been delayed under AT&T further. The Taiwanese tech giant’s VP of Product Management Mo Versi, who is very active in Twitter, revealed this information recently.

However, Versi did not indicate the reason for the delay. Speaking of new timeframe, HTC will be rolling out this update in the next couple of weeks.

Here is Versi’s tweet confirming the postponement:

Meanwhile, the Android 6.0.1 Marshmallow update for Samsung Galaxy S6 has been rolled out by Sprint and Verizon. T-Mobile, on the other hand, recently released the OTA update in phases. Now, Samsung has acknowledged that AT&T’s Galaxy S6 will be receiving the Marshmallow update very soon.

Sam Mobile noted that the support page specific to AT&T’s Samsung Galaxy S6 said upon downloading and installing the update, the software version should show G920AUCU3CPC2. Even though, AT&T has not updated its official social media accounts with the possible roll out date, Samsung’s website clearly said the firmware package has started rolling out.

In the meantime, AT&T customers can manually look for notifications by navigating to Settings -> About device -> Software update. Prior to downloading and installing the firmware package, device owners are advised to have a stable Wi-Fi connection, in addition to having at least 50 percent of battery charge left in their Android handset.

In addition, AT&T and T-Mobile have started rolling out the Android 6.0 Marshmallow update for the long-awaited LG G3 in the U.S. As the OTA updates are rolled out in phases, it might take a couple of days before all the G3 units get updated.

Verizon exclusive Motorola Droid Turbo 2 has also started receiving the Android 6.0 update.