First, thank you for answering.
How can I check the water temp? If it's the reading of "H80i v2 temp" on Corsair Link then no, it does not get any close to 50C.
The AIO is already placed as intake. I am pretty sure that the pump and fans works just fine.
Even if I wanted to switch to a better AIO with a bigger rad, I won't be able to do that since I have Zalman Z11 Plus.
I do not believe the block is getting a bad contact with the CPU, everything is installed and mounted correctly. Might be the unglued IHS though but probably should not matter that much.
Probably one of the factors is that it's very very hot where I live.