Getting errors in tapered design

Hi everyone,

It is very weird that I am getting different utilization factors every time I run the analysis (The software picks different forces values at the tapered element) and for some reason, all sections have the same utilization value. Could you check my code, please?

STAAD SPACE
START JOB INFORMATION
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 0 6.9 0; 3 14.75 10.525 0; 4 29.5 0 0; 5 29.5 6.9 0; 6 8 0 0;
8 14.75 0 0; 9 8 8.8661 0; 10 26.5867 7.61598 0; 11 17.8468 9.76393 0;
12 13.2925 10.1668 0; 13 16.2068 10.167 0;
MEMBER INCIDENCES
1 1 2; 2 2 9; 3 4 5; 4 5 10; 5 6 9; 6 8 3; 7 9 12; 8 10 11; 9 11 13; 10 12 3;
11 13 3;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 2.05e+008
POISSON 0.3
DENSITY 76.8195
ALPHA 1.2e-005
DAMP 0.03
TYPE STEEL
STRENGTH FY 253200 FU 407800 RY 1.5 RT 1.2
ISOTROPIC STAINLESSSTEEL
E 1.9793e+008
POISSON 0.3
DENSITY 76.8195
ALPHA 1.8e-005
DAMP 0.03
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
1 3 TAPERED 0.216 0.004 0.366 0.15 0.008 0.15 0.008
5 6 TAPERED 0.266 0.005 0.266 0.15 0.008 0.15 0.008
2 TAPERED 0.262 0.004 0.262 0.15 0.006 0.15 0.006
MEMBER PROPERTY AMERICAN
8 TAPERED 0.262 0.004 0.262 0.15 0.006 0.15 0.006
4 TAPERED 0.562 0.004 0.262 0.15 0.006 0.15 0.006
9 TAPERED 0.262 0.004 0.262 0.15 0.006 0.15 0.006
10 TAPERED 0.262 0.005 0.645 0.15 0.006 0.15 0.006
7 TAPERED 0.262 0.004 0.262 0.15 0.006 0.15 0.006
11 TAPERED 0.262 0.005 0.645 0.15 0.006 0.15 0.006
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 4 6 8 PINNED
2 3 5 FIXED BUT FX FY MX MY MZ KFZ 1
LOAD 1 LOADTYPE Dead TITLE DL
SELFWEIGHT Y -1
MEMBER LOAD
1 TO 4 7 TO 11 UNI GY -1.3
LOAD 2 LOADTYPE Live TITLE LL
MEMBER LOAD
2 4 7 TO 11 UNI GY -3.6
LOAD 3 LOADTYPE Wind TITLE W+X
MEMBER LOAD
1 UNI GX 4.2
2 UNI Y 3.5
7 10 UNI Y 2.1
4 8 9 11 UNI Y 1.3
3 UNI GX 0.9
LOAD 4 LOADTYPE Wind TITLE W-X
MEMBER LOAD
1 UNI GX -0.9
2 UNI Y 1.3
7 10 UNI Y 2.1
4 8 9 11 UNI Y 3.5
3 UNI GX -4.2
LOAD COMB 5 1.4DL
1 1.4
LOAD COMB 6 1.2DL+1.6LL
1 1.2 2 1.6
LOAD COMB 7 0.9DL+W+X
1 0.9 3 1.0
LOAD COMB 8 DL+W-X
1 0.9 4 1.0
PERFORM ANALYSIS
PARAMETER 1
CODE AISC UNIFIED 2010
BEAM 0 ALL
CB 1 MEMB 1 TO 4 7 TO 11
FLX 1 ALL
FU 413688 ALL
FYLD 345000 ALL
KZ 1.5 MEMB 1 3 5 6
KY 1 MEMB 1 3 5 6
METHOD LRFD
MTY 1 MEMB 1 3 5 6
MTY 2 MEMB 2 4 7 TO 11
LY 2 MEMB 2 4 7 TO 11
TRACK 2 ALL
UNB 1.5 MEMB 1 TO 4 7 TO 11
UNT 1.5 MEMB 1 TO 4 7 TO 11
INT 3 ALL
CHECK CODE ALL
PARAMETER 2
CODE AISC UNIFIED 2010
STEEL TAKE OFF ALL
FINISH