As the original poster on this one, I wanted to share what I had found on this.
My unit is a 2021 ZForce 500, and as shown in the pic above, I have a giant hole in my exhaust. I shared the pic with some CF forums on Facebook, and about 6-7 people had the same exact looking hole on their exhaust pipe.
I also had the metal piece that broke off the muffler still attached to the bracket which mounts to the CV belt enclosure with 2 bolts.
So it appears to be a design flaw where the movement of the engine and cv transmission during trail riding eventually wears the pipe at the connection point and with temp and vibration the exhaust does not win.
Many have recommended not re-attaching the exhaust pipe (repaired or replaced) to that bottom bracket, and that is how I have mine now. I will post an update, but it feels very solid. As of now, it is connected to motor, and to the muffler (via the 3 springs) and also has the cooling vent boot stabilizing it, and it feels good.
Now for my welds to hold up …. I think it will be great.
One more note, I am not sure if a gaping hole like that was causing any performance issues while riding, so I will report back on that as well. Backfiring should be gone, but wondering if some proper back pressure will also help the motor. I rode enough with the hole this year before I realized it that I feel like my overall power on the unit may have been a little down.
Check that lower portion of the pipe where it attaches to the CV belt housing and look for early cracking.
Peace.