Gromacs DSSP Secondary structure analysis

GROMACS version: 2024.2
GROMACS modification: Yes/No
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I am doing DSSP analysis. My goal is to create plots of time based statistics of secondary structure like the one below,

But, everytime I’m getting a weird plot.
The series of commands I used,
gmx dssp -s step7_100.tpr -f step7_fit.xtc -num dssp.xvg -o dssp.dat -tu ns
And plotted the graph in XMgrace with the command,
xmgrace -nxy dssp.xvg

But my plot is looking like this,


Could you please explain what could be the reason for this?