dilepton PT cut issue?

I used the following commands:

import eft* as eft
import tt* as tt
import zz* as zz
set eft.type = signal
set tt.type = background
set zz.type = background
set main.stacking_method = normalize2one
reject (l) DELTAR(j) < 0.4
plot sPT(l[1] l[2]) 50 0 500 [PTordering]
plot vPT(l[1] l[2]) 50 0 500 [PTordering]
plot MET 50 0 500
reject sPT(l[1] l[2]) < 150 [PTordering]
reject MET > 30.0
submit

Even though the plots are showing resonable distinction between signal and background for both vPT and sPT, the cuts are producing almost negligible reduction of background.

This is the dataset table for sPT case:

Dataset
eft
tt
zz

Integral
1.0
1.0
1.0

Entries per
event
1.0
1.0
1.0

Mean
613.386
38.538
74.0675

RMS
477.2
22.17
56.92

%under
flow
0.0
0.0
0.0

%overflow
56.67
0.0
0.0

The Cut Flow is as follows:

Initial (no cut)
REJ: sPT ( l[1] l[2] ) <150.0

Signal (S)
2552
2551.16 +/- 1.13

Background (B)
228439
226896.2 +/- 39.1

S vs B
5.31
5.32594 +/- 0.00239