AR15 22LR Conversion Kit for Training

I purchased a new 22LR conversion kit for my 556 M4 rifle so that I had an economical alternative for training and for the kids to use. Over the past couple of years of owning it, its broke twice now. The first time was at the rear where the buffer of the rifle meets up with the conversion kit. I heard this is a common problem since the factory does not weld that part very well. CMMG was quick to issue me an RMA number and return it with a much more durable weld. The latest breakage is the 5.56 adapter part of the kit. From the pictures below you can see how a crack developed along the length of the chamber sleeve. Needless to say I was disappointed that I had to end my shooting session early because of this. But to my delight, CMMG is sending me a replacement adapter after sending them a picture of the crack. Has anyone else experienced issues with their 22 conversion kits?