Why do I have to press home & power button to turn on my phone?

Hey guys, most of my family members owns a One Plus. However for a few weeks now, if my phone turns off or if I turn it off, the only way I can turn it on is by pressing the home button and the power button. If I only press the power button, it won't turn on. However, before it started doing this, I was able to only press the power button. Now, my sibling's One Plus is also doing the same thing. She owns the 5t and I own the 3t. Is it from the new update or a common problem?