Last month, Sony began upgrading the Xperia Z5, the Xperia Z4 Tablet, and the Xperia Z3+ to Android 7.0 Nougat. But shortly after that process began, the company suspended its rollout, due to "inconsistencies in Nougat".
Today, Sony has announced that its Nougat upgrade program has resumed for all three of those devices. It had previously stated that the issues with the update were related to "audio playback via third-party apps and SD card encrypted data read performance". Almost three weeks after the rollout was halted, it appears those issues have been resolved to Sony's satisfaction.
Sony continues to upgrade its devices to Android 7.0, but since that version was made available, Google has since released Android 7.1 and Android 7.1.1, and is now beta-testing Android 7.1.2. It's not yet clear when any of those newer versions will make their way to the Xperia range.