Most of us assume everything is right with a new computer. Sometimes that is not true.
I seldom see memory issues. However, I just checked out a computer that would not recognize some of its memory. This one was used for gaming and had 4 GB of RAM. The customer had tried to analyze the problem, but ended up with the computer seeing only 1 GB.
I assumed the problem to be either the memory slots or the memory. I tried different combinations of memory until I eliminated the slots as the problem. I ended up with two bad memory sticks.
I replaced both of them. The computer then rebooted showing 4 GB of RAM.
The customer then said, “Oh, we’ve always seen 2.5 GB.”
Their computer was just out of warranty. But their memory was bad from the start.
Check your RAM. It is probably fine, but are you seeing all you bought?