I looked over and over again, at the spot where the gravestone has a slab, and I cannot find it for the life of me! Was it changed? I cannot find it

How do I get him to show up? I've been trying to for the last 3 days. I got the autocam, while investigating the Poltergiest and he still won't show up. Is there a special condition I'm missing? I have my notebook filled to the brim with notes on him. I'm in the hallway, and the bedroom for context....

Ok I might just be dumb but I just got the game and I'm supposed to enter the office to check emails. I assume the office is the black door? (hell maybe that's where I'm dumb) but when I interact with it (using F which is supposed to be the interact key) it just pulls up the pause menu. Everything else that has a hand I interact with when I press F it is only the black door that causes this. What do I do? Is the black door not the office? Where is the office then cuz I can't interact with the computer in t...

Is there a limit to how many EVP's you can get from a ghost in one investigation? If so, how many?

I've been playing for a good 20 minutes, and not only has the Demon never shown up, but it has never given me any Temperature Data! Is there something I'm missing, or am I doing it wrong?