Update: So, after some testing I found a solution. Changing the section size or padding doesn't help. The only workaround is to split the input video before actual processing. I use a combination of batch script and ffmpeg so this is not a big deal but I then have to run the DAIN process on all segments (25 segments in my case) manually.
Is there any way to control the DAIN app via the command line so that I could automatize the whole process? It would be extremely helpful for me!