Issues with new Diamondback Sync'r

EDIT: I found out Diamondback has a local bike shop they honor warranty work for and since I just got it about a month ago I dropped it off with them. The tech said the freewheel cassette seems frozen and that Diamondback has had previous issues with them in the past so it feels it should be under warranty.

Hey guys, so early last month I ordered a Diamondback Sync'r and I've liked it so far and was even able to take it out to Turnbull canyon about two weeks ago. For the past week though the things been out of commission while I tried to do a tubeless conversion. After about a week of trying I gave up and just bought some slime tubes tonight which were working great up until about halfway through my ride tonight.

My bike started to make weird clicking/popping noises and so I stopped and tried to see what it was only to notice that it was the rear wheel making it while I moved the pedals by hand. Thinking maybe it was just some dirt or whatever I got back on and started peddling. Not too far down the road it started to make a loud screeching noise so of course I stopped and looked again, I started to move the peddle and moved to the biggest cog only to notice that it wouldn't stay on it, it would hop down to the next lowest one.

I then tried the smallest cog and the chain actually got jammed between the body and cog after a couple of hand peddles. I took off the wheel tried to see if I could see anything amiss in the dark but couldn't see anything. I also noticed from a couple of tries that the sound and how quickly it came back was dependent on how tightly I screwed the long screw that holds the wheel in place. The tighter I made it the less likely it would jump cogs but would still do it every so often.

Another thing I noticed is that if I peddled backwards with my hand, the wheel will spin, I'm not sure if it did that before but it will catch the wheel if I start peddling forward with my hand and then go backwards. If I'm peddling with my feet the chain will come off if I stop peddling.

What could have caused this? When I last rode and got a couple flats the thing was fine and I honestly don't think I've hit 20 miles with it yet. Is this normal?