Hi. I just made this for the Ender 3 Pro. I only broke one piece, and I could tell it was going to break because it was a bad print. Yours are breaking because it looks like your machine is over-extruding. You shouldn't have those layer separations in your pieces. I'm also using Cura. I will tell you my settings, but you will need to calibrate your printer. Check out this video and it will walk you through the process. https://youtu.be/3yIebnVjADM My settings are 195-205 degrees for the hotend, 60 degrees on the bed, .2mm layer height, 100% infill, enable retraction 5mm, speed 30-45, and use a brim on the smaller pieces like the link covers. And the BLTouch works great.