RAM Upgrade Issue

Hi, I decided at the start of the year to upgrade my RAM. I have Aspire V5-572P-9655. When I bought the laptop there was a 4gb Kingston memory module in the 1 slot. I discovered over the holidays that there is 4gb memory on the motherboard. So I had 8gb memory when I bought the laptop years ago. I also learned over the holidays that the max install memory is 12 gb. So I ordered an 8gb memory module. The first module (a crucial stick) I ordered was not accepted at all by the computer. So since the computer worked with Kingston, I went to their site and entered the laptop that I have and it came back that part number KCP3L16SD8/8 is supposed to work. So i ordered that and the computer accepts it BUT control panel says I have still only 8 gb installed. I went into the BIOS and it won't allow me to change the memory setting. Why? Do I need a BIOS update?

I see lots of people have the same issue when upgrading their RAM. Why does this have to be so difficult???? Can't designers make this plug and play like a lot of hw/sw! It's some frustrating.

Thank you, Darryl