Contours all getting labeled as zero in my contour plot

Question

As you can see from the plot below, my contour plot renders several contour lines. The legend shows the how values change with colors.

However, all the contour lines on the plot are labeled 0, which is wrong because the value is changing with color. The real 0 contour should be the middle one.

What is the problem here, and how can I correct it?

c = 1;
NN = 0.365*10^19;
GradN = -9.42*10^19;
Te = 143;
λDe = 7.43*1000*Sqrt[Te/NN];
λDi = 7.43*1000*Sqrt[Ti/NN];

lne = Log[4*Pi*NN*λDe^3];

lni = Log[4*Pi*NN*λDi^3];
νi = 4.8*10^(-14)*NN*lni/(Ti^1.5);
νe = 2.9*10^(-12)*NN*lne/(Te^1.5);
Me = 9.109*10^-31;
Mi = 1.672*10^-27;
e = 1.602*10^-19;

R = 1.5; (*m*)
a = 0.2; (*m*)
ϵ = a/R;
B = 1;
BT = 0.955;
BP = Sqrt[1 - BT^2];(*rw*BT/(R*qs) B=Sqrt[BT^2+BP^2]*)

Clear[r]
ι0 = 1.551;
ι1 = 0.05238;
ι2 = -0.07569;
ι3 = 0.12862;
qr = 1/(ι0 + ι1*r/a + ι2*r^2/a^2 + ι3*r^3/a^3);

m = 5;(*m,mode,number*)
n = 8;
risola = Solve[qr - m/n == 0, r, Reals];
rw = r /. risola[[1]];
dw = 0.01;(*Width of the island 1cm*)
δw = dw/R;(*Width divided by major radius R*)

Plot[1/qr, {r, 0, a}, GridLines -> {{rw}, {m/n}}];

Clear[r];
dqr = D[qr, r];
r = rw;
dqs = dqr;
qs = qr;

Clear[r];
ve = Sqrt[2*Te*e/Me];
vi = Sqrt[2*Ti*e/Mi];
νerefe = 10^-4*ve/(qs*R);
νirefe = 10^-2*vi/(qs*R);
ωbe = ve/(R*qs);
ωbi = vi/(R*qs);
νe = νe/ωbe;
νi = νi/ωbi;

drdΦ = 1/(2 Pi*BP*R)/(dqs*dw/qs);
H = Exp[-((r/a - rw/a)/dw/a)^2];
G = Exp[-((r/a - rw/a)/dw/a)^2];

xx = 100;
C1e = (Te/(B*r))^2;
C1i = (Ti/(B*r))^2;
ωE = drdΦ*Er/(B*r);

gammadwscanee = -(GradN + NN*Er/Te)*(drdΦ)^2*
   C1e*(νe*
     ve/(qs*R)/(ϵ))*(R*BP)^2*(dqs*
      dw/qs)^2*(m*δw)^2*ϵ^(0.5)/(ωE^2*(R*
          BP)^2*(dqs*dw/qs)^2*
       m^2/(0.22*G) + (νe*ve/(qs*R)/ϵ)^2/(0.5*H));
gammadwscanii = -(GradN - NN*Er/Ti)*(drdΦ)^2*
   C1i*(νi*
     vi/(qs*R)/(ϵ))*(R*BP)^2*(dqs*
      dw/qs)^2*(m*δw)^2*ϵ^(0.5)/(ωE^2*(R*
          BP)^2*(dqs*dw/qs)^2*
       m^2/(0.22*G) + (νi*vi/(qs*R)/ϵ)^2/(0.5*H));
gammadwscan = Numerator[Together[gammadwscanee - gammadwscanii /. r -> rw]]

ContourPlot[gammadwscan, {Er, -5000, 5000}, {Ti, 20, Te}, 
  PlotLegends -> Automatic, ContourLabels -> All]    

Answer 1

It looks as if Mathematica's contour labeling can not handle the immense range of your plot. When the gammadwscan is scaled down, everything looks good.

ContourPlot[gammadwscan/1*^40, {Er, -5000, 5000}, {Ti, 20, Te},
  ContourLabels -> All,
  PlotLegends -> Automatic]