Time Capsule Backup is "Freeing space" for hours now.
I use a Time Capsule to backup my 2015 MacBook Pro (which is itself a backup of my newer 2019 MacBook Air). Once a week I copy all the files from my Air to my Pro, then manually backup my MacBook Pro using Time Capsule. When I did it today, there was 40 GB of space on the Time Capsule, for what is a 31 GB backup up. After backing up 17 GB, the Time Capsule progress window showed "Freeing space..." and has been doing that now for almost 5 hours.
Is this typical for freeing space? Or is it stuck in some loop? I have to leave for a trip in the morning and wanted to have my backups completed, but now I'm worried it will continue to free space through the evening. Is there something I can do speed up the process?
Also, there appeared to be space for this backup, so not sure why it stopped backing up and started freeing space. Currently I have about 2 years worth of backups on Time Capsule, but honestly only need a single instance of the MacBook Pro incase it crashes AND the MacBook Air does too. Is there another way to use my MacBook Pro and Time Capsule to provide redundant backups for the Air?
MacBook Pro 13″, macOS 10.15