Aircrete blocks cracking to the gables

[Will A]

Hi,

 

Looking for some input regarding the sudden appearance of cracking to the Aircrete blocks to the gables.

 

The house was built in 2016/17, the mortar used to construct the block walls is M4.

Cracking to one gable started to appear 5 months ago, and to the second last month.

The run of the wall is just over 8.5 meters and no movement joints were installed, the outer leaf is brick.

 

Should I be concerned?

 

Thanks in advance

 

The white X marks where each crack is, the cracks appear to run vertically and the mortar is also cracking.