A little tutorial about fixing "cut off" fractals in Mandelbulb 3D
just a little note, in some cases, unlike the tutorial, you may have to use an even smaller number for the Z Start... in my render "cages"
I first changed the Z Start as in the tutorial, just a small amount, but that did not move it enough... I doubled the amount that I changed it, and still the tubes were cut off... I ended up going from something typical like -1.5 to something like -40 or -50 to fix it, so you may find you have to use lower and lower numbers until you finally reach the place you need.
Just remember, negative numbers move away, positive number move closer, and never forget -2 is SMALLER than -1