If you have 2 RAM modules they should normally be inserted into slots next to each other and in the slots closest to the CPU. Try moving the module that's in slot A3 into slot A1 and see if it registers correctly.
Huawei P10 review
1995-2015: How technology has changed the world in 20 years
An overview: What leading creative agencies are doing to improve diversity
New iPad, iPhone SE & Red iPhone 7 on sale now