paste: error on serial

[iingLK]

Environment: Microsoft Windows [Version 10.0.19045.5247]
Installation: winget install uutils.coreutils
Installer Url: https://github.com/uutils/coreutils/releases/download/0.0.28/coreutils-0.0.28-x86_64-pc-windows-msvc.zip

Steps to reproduce:

seq 15 | coreutils paste -sd ","

What happens now: visible output shows

,15

but if i do seq 15 | coreutils paste -sd ","|clip the output become

1
,2
,3
,4
,5
,6
,7
,8
,9
,10
,11
,12
,13
,14
,15

What I expected to happen: it should appear as 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

Note:

• using coreutils seq 15 | coreutils paste -sd "," give me the correct output 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
• I'm using seq --version : seq (GNU sh-utils) 1.13 it s not coreutils seq
• i do this experiment since dir *.exe/b | coreutils paste -sd "," doesnt give proper output