ffmpeg xfade apply to images cause black screen

[slick zheng]

I try to add transition in the input images, each image has a duration, the command is below:

ffmpeg -t 8.34 -i ./tmp/HHA44m/script_1_image_20240326_211935.png -t 9.719999999999999 -i ./tmp/HHA44m/script_2_image_20240326_211958.png -t 9.96 -i ./tmp/HHA44m/script_3_image_20240326_212013.png -t 8.360000000000003 -i ./tmp/HHA44m/script_4_image_20240326_212028.png -t 8.799999999999997 -i ./tmp/HHA44m/script_5_image_20240326_212045.png -t 8.380000000000003 -i ./tmp/HHA44m/script_6_image_20240326_212059.png -i ./tmp/HHA44m/input.mp3 -filter_complex "[0:v]scale=8000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='x-10':y='y':d=209[v0];[1:v]scale=8000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='x+10':y='y':d=243[v1];[2:v]scale=8000x4000,zoompan=z='min(zoom+0.0015,1.5)':y='if(gte(ih,y),ih,y)-10':x='x':d=249[v2];[3:v]scale=8000x4000,zoompan=z='min(zoom+0.0015,1.5)':y='y+10':x='x':d=209[v3];[4:v]scale=8000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='x-10':y='y':d=220[v4];[5:v]scale=8000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='x+10':y='y':d=210[v5];[v0][v1]xfade=transition=slideleft:duration=1:offset=7.34[x0];[x0][v2]xfade=transition=slideleft:duration=1:offset=17.06[x1];[x1][v3]xfade=transition=slideleft:duration=1:offset=27.02[x2];[x2][v4]xfade=transition=slideleft:duration=1:offset=35.38[x3];[x3][v5]xfade=transition=slideleft:duration=1:offset=44.18,format=yuv420p[v]" -map "[v]" -map 6 -s 1024x1792 ./tmp/HHA44m/concat.mp4

the transition in expectation is start at one second before the end of each image. But I got a black screen in the result video at 17s. is my xfade offset wrong?