Need help I’ve drawn a blank‼️

How you guys doing, I’m new to posting on here definitely learned alot from your other posts helped me rebuild my 03 ltz400, but I do have a problem now so I rebuilt the whole motor.Everything new besides cams were still in great shape, bikes been running for about a month but in the middle of the build I broke my foot it’s only been rode around the yard an neighborhood today I was riding it cruising around giving my son a ride when it made a weird noise on the timing chain side when the bike cut off. Mind you I took off casually went through the gears smoothly till I hit third when it did it, bike does like a noise as if it’s spinning gears but basically no compression it dosent even seem like the crank is moving, still rolls through all gears it almost feels like there’s no timing chain in the motor if you understand what I mean any ideas would be appreciated im fairly new to the building bike world probably about a year in still learning though lol