extundelete will not be able to find deleted files

Hello

It seems to me that extundete should easily find some accidentally deleted files

Versions
cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=19.10
DISTRIB_CODENAME=eoan
DISTRIB_DESCRIPTION="Ubuntu 19.10"

extundelete -v
extundelete version 0.2.4
libext2fs version 1.45.3
Processor is little endian.

Context: USB partition and contents of a repertory
ls -l /mnt/USB-b/REP4
total 2949144
-rw-r--r-- 1 a a 42991616 janv. 21 14:41 Fic1
-rw-r--r-- 1 a a 429916160 janv. 21 14:41 Fic10
-rw-r--r-- 1 a a 430964736 janv. 21 14:41 Fic11
-rw-r--r-- 1 a a 432013312 janv. 21 14:41 Fic12
-rw-r--r-- 1 a a 433061888 janv. 21 14:41 Fic13
-rw-r--r-- 1 a a 434110464 janv. 21 14:41 Fic14
-rw-r--r-- 1 a a 435159040 janv. 21 14:41 Fic15
-rw-r--r-- 1 a a 44040192 janv. 21 14:41 Fic2
-rw-r--r-- 1 a a 45088768 janv. 21 14:41 Fic3
-rw-r--r-- 1 a a 46137344 janv. 21 14:41 Fic4
-rw-r--r-- 1 a a 47185920 janv. 21 14:41 Fic5
-rw-r--r-- 1 a a 48234496 janv. 21 14:41 Fic6
-rw-r--r-- 1 a a 49283072 janv. 21 14:41 Fic7
-rw-r--r-- 1 a a 50331648 janv. 21 14:41 Fic8
-rw-r--r-- 1 a a 51380224 janv. 21 14:41 Fic9

The big mistake
export LC_ALL=POSIX
rm -v /mnt/USB-b/REP4/*
removed '/mnt/USB-b/REP4/Fic1'
removed '/mnt/USB-b/REP4/Fic10'
removed '/mnt/USB-b/REP4/Fic11'
removed '/mnt/USB-b/REP4/Fic12'
removed '/mnt/USB-b/REP4/Fic13'
removed '/mnt/USB-b/REP4/Fic14'
removed '/mnt/USB-b/REP4/Fic15'
removed '/mnt/USB-b/REP4/Fic2'
removed '/mnt/USB-b/REP4/Fic3'
removed '/mnt/USB-b/REP4/Fic4'
removed '/mnt/USB-b/REP4/Fic5'
removed '/mnt/USB-b/REP4/Fic6'
removed '/mnt/USB-b/REP4/Fic7'
removed '/mnt/USB-b/REP4/Fic8'
removed '/mnt/USB-b/REP4/Fic9'

the start of the repair
sudo umount -v /dev/sdb2
umount: /mnt/USB-b (/dev/sdb2) unmounted

repair that doesn't work
sudo extundelete /dev/sdb2 --restore-all
NOTICE: Extended attributes are not restored.
Loading filesystem metadata ... 2000 groups loaded.
Loading journal descriptors ... 0 descriptors loaded.
Searching for recoverable inodes in directory / ...
0 recoverable inodes found.
Looking through the directory structure for deleted files ...
0 recoverable inodes still lost.
No files were undeleted.

This context is a reproduction of errors that have occurred in the French forum and that have not been resolved. I think I did not make a mistake in use.

Thank you for your opinion