Mandelbrot Julia zoom distorted coloring

Why do I get this blurred distorted coloring? An inverse julia zoom:

MandelbrotJuliaZoomIncorrectColoring {
fractal:
  title="Mandelbrot Julia zoom incorrect coloring" width=800
  height=600 layers=1 credits="Kathy;6/23/2020"
layer:
  caption="Background" opacity=100
mapping:
  center=0.000993846291914812695705/0.000381483804274999567745
  magn=1.2142773E10
formula:
  maxiter=50000 percheck=off filename="Standard.ufm" entry="Julia"
  p_seed=-1.7016966264854691610791197/1.6659292699665812152390969e-7
  p_power=2/0 p_bailout=4
inside:
  transfer=none
outside:
  transfer=linear filename="Fractint.ucl" entry="outside"
  p_outside=iter p_n=1 p_logmap=0 p_biomorph=-1 p_bailout=100.0
  p_smooth=yes
gradient:
  linked=yes smooth=no rotation=48 index=405 color=16021756 index=424
  color=13381864 index=449 color=3539002 index=49 color=0 index=50
  color=208896 index=99 color=1627136 index=107 color=11074720
  index=118 color=2154496 index=156 color=272896 index=157 color=0
  index=185 color=8961084 index=207 color=14807453 index=227
  color=10016836 index=256 color=1060105 index=257 color=3932160
  index=314 color=16756533 index=361 color=3678208 index=362
  color=786452 index=385 color=7078028
opacity:
  smooth=no rotation=48 index=405 opacity=255 index=424 opacity=255
  index=449 opacity=255 index=49 opacity=255 index=50 opacity=255
  index=99 opacity=255 index=107 opacity=255 index=118 opacity=255
  index=156 opacity=255 index=157 opacity=255 index=185 opacity=255
  index=207 opacity=255 index=227 opacity=255 index=256 opacity=255
  index=257 opacity=255 index=314 opacity=255 index=361 opacity=255
  index=362 opacity=255 index=385 opacity=255
}

For some reason, Ultra Fractal doesn't realize here that it should switch to Extended precision for the calculation. You can force this by entering "2" for the Additional Precision value in the Formula tab.

I'll investigate why this doesn't happen automatically.

Thanks very much, Frederik! That fixes it.

To clarify, I found the value "2" by experimenting. You don't want to add too much precision to avoid going into the Arbitrary Precision domain (which is much slower). So just a little bit until the Statistics tool window shows that Extended precision is used instead of Double.

https://www.ultrafractal.com/help/formulas/arbitraryprecision.html
https://www.ultrafractal.com/help/workspace/statistics.html

For the standard Mandelbrot Set, the switch to higher precision works mostly fine, but there are some regions where it doesn't switch in time and this is what you get. It also happens if you do a circle inversion and the centre is very close to the set, such that the inverted set becomes very large and you have to zoom out to actually see it all.

I am not sure if this can be easily fixed since different regions of different fractals don't always need the same amount of decimals to be properly rendered.

Just in case this helps: one region where I was consistently able to reproduce this problem is the antenna of the power 2 Mandelbrot set, specifically out toward -2 on the real axis, zoom into one of the mini Julia sets on the real axis and just keep zooming, you'll hit the limit eventually and have to manually adjust precision, at least for me this has consistently been the case.