Thunar 4.20.1 issue – some files not shown in long lists

[Piscium]

Hi all,

First my thanks to the Xfce developers for the new 4.20 version.

This week I noticed an issue when I used Thunar on a folder that has a
few hundred files. As usual I was using Thunar in the 'compact list
view' mode. Because there were more files in the folder that could be
displayed in the Thunar window I used the arrows to scroll Thunar to
the left and right. I was looking for a file that I knew existed but
it was not shown according to its alphabetical order. I pressed F5 to
refresh and that file appeared. But shortly after I was looking for
another file which too did not appear, I pressed F5 to refresh and
that file appeared. F5 seems to refresh, but not the whole folder,
apparently it refreshes only some files near the one I am looking at
by alphabetical order.

For a bit of context, I am using Thunar 4.20.1 on Arch Linux, the
system language is English. The names of the files are all in
ASCII/UTF8. I could not take screenshots because the source tree I was
looking at is proprietary. The file names are built with English
abbreviations separated by underscores, something like:
prep_auto_a
prep_auto_b
prep_carb_b1

The names can be longer than that, like with 25 characters.

The tour of 4.20 [1] mentions changes to Thunar for performance. I am
left wondering if what I saw was an unintended effect of those
changes.

[1] https://www.xfce.org/about/tour420