Skin session & minecraft do not cooperate

Basically what I want to do, is set a head to obtain in game. I changed my skin via the launcher, inserted my UUID in the <uuid> and obtained the Base64 code. Then I pasted it (properly) and when I power the command block, I get the wrong head. However, when checking what my skin is via namemc, or using a decoder for the Base64, the skin is correct. The minecraft command blocks just give the wrong skin head for some reason

https://sessionserver.mojang.com/session/minecraft/profile/ <uuid> is the link I use.