Unable to resize APFS partition after removing bootcamp - APFS resize error code 49180

Hi there, I appreciate any help regarding this.

Mac Mini (Late 2012)

Current OS: macOS Catalina 10.15.7

Fusion Drive of 1.12TB, split into a 121GB SSD and 1TB HDD

Here's a breakdown of the disks and identifiers:

I recently moved to macOS Catalina, from Mojave. I had a bootcamp partition with a size of roughly 160GB, which was created (from memory) while on the Mojave OS. I used the bootcamp assistant to remove the bootcamp partition, but was met with an error that it was not able to resize the APFS container. You'll notice that container scheme is 959GB instead of 1,121GB, the 'missing space' is free space, as I can see in disk utility, and is the same size as what the bootcamp partition was.

I then attempted to use disk utility to partition the 'Fusion drive', removing the 'free space' partition, and allowing the Macintosh HD to recover its full capacity. This failed, and so I tried it on 'Container disk2' - here's the error for the attempt on Container 2;

Disk utility both fails to remove the 'free space' partition and to resize the APFS volume of Macintosh HD.

I tried using terminal to 'manually' resize the partition, you'll notice in italics, is where I attempted to resize the container scheme rather than the container disk2 -

I had a full Time Machine backup, before attempting the above - I appreciate any help, I would imagine I'm close but off the mark with regards to solving the issue

Best

Michael