Bonsoir. Même souci pour moi, suite au même aller-retour entre Mojave et Catalina...
Et quel est l'intrus dans mon cas :
/dev/disk0 (internal):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme 28.0 GB disk0
1: EFI EFI 314.6 MB disk0s1
2: Apple_APFS Container disk2 27.6 GB disk0s2
/dev/disk1 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk1
1: EFI EFI 209.7 MB disk1s1
2: Apple_APFS Container disk2 1000.0 GB disk1s2
/dev/disk2 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +1.0 TB disk2
Physical Stores disk0s2, disk1s2
1: APFS Volume Macintosh HD 202.8 GB disk2s1
2: APFS Volume Preboot 54.0 MB disk2s2
3: APFS Volume Recovery 510.3 MB disk2s3
4: APFS Volume VM 2.1 GB disk2s4
5: APFS Volume Données new 308.4 GB disk2s5
/dev/disk3 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *2.0 TB disk3
1: EFI EFI 209.7 MB disk3s1
2: Apple_HFS Seagate - Time Machi... 2.0 TB disk3s2