My Catalina Startup Disk space has disappeared after trying to merge partitions

Hi, thanks for replying, but it has nothing to do with removing Windows. I do not want to remove Windows, and I have not removed Windows Bootcamp from my computer.

As you can see above, (screenshots) my bootcamp still exists, and I still need it.

I was trying to merge my old partition of mac OS High Siera with the new OS Catalina. I had separated two partitions on the same disk (as explained above) and when I tried to merge the High Siera partition after a successful upgrade to Catalina, it "disappeared". Am I wrong? Is there any way to fix this?

Last login: Wed Nov 11 10:42:10 on console

theo@Theo-Mac-Pro ~ % diskutil list

/dev/disk0 (internal, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   GUID_partition_scheme            *1.0 TB   disk0

  1:            EFI EFI           209.7 MB  disk0s1

  2:         Apple_HFS HD           9.0 GB   disk0s2

  3:    Microsoft Basic Data BOOTCAMP        990.9 GB  disk0s3

/dev/disk1 (internal, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   GUID_partition_scheme            *2.0 TB   disk1

  1:            EFI EFI           209.7 MB  disk1s1

  2:         Apple_APFS Container disk2     999.4 GB  disk1s2

/dev/disk2 (synthesized):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   APFS Container Scheme -           +999.4 GB  disk2

                 Physical Store disk1s2

  1:        APFS Volume Catalina - Data     467.2 GB  disk2s1

  2:        APFS Volume Preboot         45.9 MB  disk2s2

  3:        APFS Volume Recovery        731.7 MB  disk2s3

  4:        APFS Volume VM           1.1 MB   disk2s4

  5:        APFS Volume Catalina        11.2 GB  disk2s5

/dev/disk3 (internal, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   GUID_partition_scheme            *4.0 TB   disk3

  1:            EFI EFI           209.7 MB  disk3s1

  2:         Apple_HFS Theo          4.0 TB   disk3s2

/dev/disk4 (internal, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   GUID_partition_scheme            *2.0 TB   disk4

  1:            EFI EFI           209.7 MB  disk4s1

  2:         Apple_HFS Back Up         2.0 TB   disk4s2

Indeed,

I used the diskutil, and terminal commands that were suggested on the site....

I don't want to erase the disk unless Im sure that it will actually solve the problem. Its also the startup disk of my computer.

Then we leave this open, if there is a solution to be found in the future.

As I read on that site, some others had a similar or same result, but no replies to their issues, that is why I opened this discussion. By the way Bootcamp Assistant is not supported on my computer it says.

Thank you very much for your efforts :)!

The Catalina partition was made BEFORE the one I deleted. Because I wanted to see if Catalina would actually be installed on my computer. So I had made 2 partitions, the first was High Siera (which was my startup disk) and then the new partition Catalina. When Catalina was a success installation, I migrated everything, checked is everything was ok and then I tried to merge ..... (etc)

I tried First Aid as you said, it says operation successful but nothing changes

Note: My Bootcamp is on a separate Disk.

Thanks Barney, I tried that, but its not possible as you can see from the screenshot, it is as if its 1 partition of 999GB with 479.39 used which cannot be split, but it is on a 2TB disk.

No, I followed part of it, I didnt want to merge the partition of Bootcamp, I didnt want to remove Bootcamp. But only merge APFS partition,

sorry I got confused, yes obviously Catalina was after High Sierra