250Gb HDD out of 500 Gb mising I face very similar description as in this post here
50GB of disk space missing

I did post an additional question in that thread and was recommended to open a separate question .

After migrating to Catalina, I ended up with multiple containers and disks. I removed 1 container but fail to recover the space that was used by this extra container.

When trying to fix the issue here was my situation.


Next I removed the EFI disk 

sudo diskutil eraseVolume "Free Space" %noformat% /dev/disk0s1

When running the command : 

diskutil apfs resizeContainer disk0s2 0

error reply remains : Started APFS operation
Error: -69743: The new size must be different than the existing size

So I'm stuck in this situation with half of my disk storage capacity missing.
The current partition map of your internal HDD looks like this:

    start       size  index  contents
        0          1         PMBR
        1          1         Pri GPT header
        2         32         Pri GPT table
       34  488722422         
488722456  488050672      3  GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC
976773128          7         
976773135         32         Sec GPT table
976773167          1         Sec GPT header


The partition with the index 3 is your APFS container container disk1 housing HDD, HDD - Données, and other APFS volumes.

Before removing the EFI partition (index 1/disk0s1) it looked like this (with a giant gap between the EFI and the APFS container):

    start       size  index  contents
        0          1         PMBR
        1          1         Pri GPT header
        2         32         Pri GPT table
       34          6
       40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
   409640  488312816
488722456  488050672      3  GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC
976773128          7         
976773135         32         Sec GPT table
976773167          1         Sec GPT header


You can't expand a partition to lower block numbers (i.e. moving the first block of the container (index 3) from block 488722456 to block 409640).

The partition with the index number 2 resided in the empty space and was removed earlier.


  I removed 1 container but fail to recover the space that was used by this extra container




I recommend to get an external drive, set it up as Time Machine backup drive and backup your internal drive.

Then format the internal drive (booted to Internet macOS Recovery) to GPT/APFS, install macOS Catalina and migrate your user data from the Time Machine backup to the internal drive.