Parted TS fragments don't handled correctly

[Uncle Feudor]

Hi there!
Did anybody manage to use mux.js for transmuxing partial .ts segments? I faced with the following issue:
I have a 2s-duration common segments and 500ms-duration partial segments (4 partial segments per one common). If I'm trying to parse partial ts's via debug page, the source buffer behaves very strangely:

end of first mediaBuffer is set to ~500 ms after parsing first partial segment (as expected)

end of first mediaBuffer is set to ~998 ms after parsing second partial segment (as expected)

end of first mediaBuffer is set to ~1001 ms after parsing third partial segment (but expected ~1500)

I also tried to change a number of parts, and it looks like it works only if there are two parts of the segment.

It causes gaps in sourceBuffer.
But moreover, if I'll concat first, second, and third partial segment into one file, transmuxer will successfully handle it and the source buffer duration will be set to 1500ms.
Thanks in advance for any help or ideas.