Projects Cancelled

I'm new here and I honestly don't know if I'm just having really bad luck. 

Almost every single project that I've submitted a proposal for has been cancelled within 14hrs of my submission. Is that really such a common thing here, or am I somehow only finding the dodgy projects?! Most of them also then have the buyer account deactivated/deleted, so I assume they've done something wrong.

I was accepted for a project last night and when I tried to open the NDA, the file was corrupt. I checked if the project was still active - it was. I checked if the buyer's account was still active - it was. I then messaged the buyer to provide a screenshot of the file corruption error notification and asked them to re-upload it. As soon as I sent that message I got a notification that the project was cancelled. I checked the buyer's account again and now they were suddenly deleted. 

I really don't know what is going on here. Is there a problem on my end? How can it be that every project I apply for is cancelled?! Surely that isn't usual?