Why doesn't .part1, .part2 work for me with Infuse?

I have a file in 2 part

title.part1.mkv
title.part2.mkv

The file is correctly detected by Plex official app as 1 playback item.

On infuse however, for some reason it won’t - It will play part1 and shows its total time, but not part2. It happens both on iOS and tvOS.

I have rescanned library multiple times both server+client. I have also tried with .pt1, .pt2 or .Part2 .Part1 capitalized.

What could be the issue?