File size reporting inside mounted repos fails with some utilities

[Juul]

File sizes are reported correctly when using ls (Ubuntu 20.04, Bash 5.0.17):

~/ouisync/eq test 1$ ls -l
total 0
-r--r--r-- 1 root root 2077184 Dec 31  1969  1-MB-DOC.doc
-r--r--r-- 1 root root  179215 Dec 31  1969  74a468de-efb8-4a59-b3d5-228b9b4e8563.jpeg
-r--r--r-- 1 root root  621322 Dec 31  1969 'dandelion-445228_1920 (1).jpg'
-r--r--r-- 1 root root  621322 Dec 31  1969  dandelion-445228_1920.jpg
dr-xr-xr-x 1 root root     119 Dec 31  1969  F2
-r--r--r-- 1 root root  334832 Dec 31  1969  fantasy-2049567_1920.jpg
-r--r--r-- 1 root root  102912 Dec 31  1969  Free_Test_Data_100KB_DOC.doc
-r--r--r-- 1 root root 1320783 Dec 31  1969  sample_960x540.mp4

but are reported as zero when using e.g. du or ncdu:

~/ouisync/eq test 1$ du *
0	1-MB-DOC.doc
0	74a468de-efb8-4a59-b3d5-228b9b4e8563.jpeg
0	dandelion-445228_1920 (1).jpg
0	dandelion-445228_1920.jpg
0	F2
0	fantasy-2049567_1920.jpg
0	Free_Test_Data_100KB_DOC.doc
0	sample_960x540.mp4

ncdu:

--- /home/juul/ouisync/eq test 1 -----------------------------------------------
    0.0   B [          ]  1-MB-DOC.doc                                          
    0.0   B [          ]  sample_960x540.mp4
    0.0   B [          ]  dandelion-445228_1920.jpg
    0.0   B [          ]  dandelion-445228_1920 (1).jpg
    0.0   B [          ]  fantasy-2049567_1920.jpg
    0.0   B [          ]  74a468de-efb8-4a59-b3d5-228b9b4e8563.jpeg
    0.0   B [          ]  Free_Test_Data_100KB_DOC.doc
    0.0   B [          ] /F2

It doesn't matter of the repo was originally created locally or synced from another peer. Behavior is the same.