how to cut a video with ffmpeg – the ss command creates freeze frames

I am trying to trim my video, with lossless quality.

but the - ss command has a 2 second freeze frame, at the start, everytime it is used

I started my code with this,

loopduplicate.com/content/lossless-video-cut-with-ffmpeg

but when I run this example,

ffmpeg -i in.mkv -ss 0:01:00 -t 0:01:30 -vcodec copy -acodec copy out0.mkv

there are 2 second of frozen frame in the VLC playback …. at the start of the output file, out0.mkv

how can I remove this 2 second delay so the file plays smoothly

when I merge out0.mkv and out1.mkv

I’m trying to achieve this

ffmpeg -i in.mkv -ss 0:00:00 -t 2:36:30 -vcodec copy -acodec copy out0.mkv

ffmpeg -i in.mkv -ss 2:36:32 -t 2:49:06 -vcodec copy -acodec copy out1.mkv

ffmpeg -f concat -i mylist.txt -c -vcodec copy -acodec copy out3.mkv

but current have 2 instance … of frozen frames … because I used the - ss command twice