Generating strange arima output may be pc-dependent
You may try

smpl 1 194
series sty=diff_series/sd(diff_series)
list zli = y_one y_two
# if paste bad_matrix32 and bad_matrix64 \$workdir there's no need to input path
arima 3 0 0; 1 0 0; y 0 zli --verbose

If both models are ok :
i.e. something like this (64)

Model 3: ARMAX, using observations 1950:1-1998:2 (T = 194)
Estimated using AS 197 (exact ML)
Dependent variable: y
Standard errors based on Hessian

coefficient   std. error      z       p-value
---------------------------------------------------------
const       6.48832      0.0467055    138.9      0.0000   ***
phi_1       0.567313     0.159434       3.558    0.0004   ***
phi_2      −0.158255     0.107503      −1.472    0.1410
phi_3      −0.120526     0.130267      −0.9252   0.3549
Phi_1      −0.0597471    0.121899      −0.4901   0.6240
y_one       0.203394     0.233933       0.8695   0.3846
y_two      −2.07615      0.389196      −5.334    9.58e-08 ***

or this (32)

Model 4: ARMAX, using observations 1950:1-1998:2 (T = 194)
Estimated using AS 197 (exact ML)
Dependent variable: y
Standard errors based on Hessian

coefficient   std. error      z       p-value
---------------------------------------------------------
const       6.38832      0.0467055    136.8      0.0000   ***
phi_1       0.567313     0.159434       3.558    0.0004   ***
phi_2      −0.158255     0.107503      −1.472    0.1410
phi_3      −0.120526     0.130267      −0.9252   0.3549
Phi_1      −0.0597471    0.121899      −0.4901   0.6240
y_one       0.203394     0.233933       0.8695   0.3846
y_two      −2.07615      0.389196      −5.334    9.58e-08 ***

you can try this

smpl 1 194
series sty=diff_series/sd(diff_series)
list zli = y_one y_two

series y = 0

matrix matr=seq(1,1000)/10^2
n = nelem(matr)
ret = zeros(n,1)

loop i = 1..n -q
y = sty+matr[i]
catch arima 3 0 0; 1 0 0; y 0 zli -q
err = \$error
ret[i] = err? -\$huge: \$lnl
endloop
eval imaxc(ret)

# note : mean(sty)~0

# than run, for example

arima 3 0 0; 1 0 0; y 0 zli --verbose

arima 3 0 0; 1 0 0; y 0 zli --verbose

arima 3 0 0; 1 0 0; y 0 zli --verbose

#############
? arima 3 0 0; 1 0 0; y 0 zli --verbose
NLS: failed to converge after 1605 iterations

Error executing script: halting
> arima 3 0 0; 1 0 0; y 0 zli --verbose
###################
expected

Oleh