Answer to "Screen won't stay off while on call"First, this situation should not be happening. I have not used S10+ but I have previously found old phones that have faulty proximity sensor that caused this. So, it might be the case for you.
Answer to "Why is my battery dying SO fast?!"I would definitely agreed that this is most likely due to the battery. This is an iPhone 6, if you haven’t replaced the battery yet, it is time to do it now.
Answer to "Can you upgrade the ram on the Surface pro 6?"The RAM is soldered to the motherboard. So, it would be extremely difficult to upgrade.
Answer to "What SSD is used in the pro 6"For the 128GB version, it is SK hynix HFB1M8M0331A (BC501) 128 GB NVMe SSD (see the teardown), and yes, it is soldered to the motherboard.