Increase virtual machine disk size might not work

Problem: I can't increase the disk size for the virtual machine, because I found that the listed number didn't match between the one showed in settings and the one showed in ubuntu disk analyzer(Screenshot 2024-12-13 at 23.08.10.png).

Host Env: Mac Pro M1
Parallels Desktop: 20 for Mac, Version 20.1.2 (55742)
Virtual Machine: Ubuntu 24.04 ARM64

How to reproduce:
1. Change the disk space for the virtual machine in settings
2. Start the virtual machine
3. Check the Disk Usage Analyzer
4. Compare the numbers, then seem don't match