A friendly WARNING to PD13 users on Mac High Sierra with SSD

Greetings,
If you are using PD13 on a Mac High Sierra machine with a SSD using Apple's APFS file system read this.
I run the latest iMac system, with a 1TB SSD. I use PD13 to run a Windows 10 VM with an expandable disk.
I create and delete somewhat large video files. Thus I usually have over 100GB of space to reclaim.
I'm not sure of the specifics, but I think the issue I'm experiencing has something to do with the APFS "purgeable space".
If you click the Apple logo, "About this Mac", then "Storage", it will calculate for a few seconds then display that you have 300GB of free space for example.
If you open Disk Utility, it will display that you have 25GB of free space on the disk.
I *think* that difference is the "purgeable space". I could be wrong.
I'm wondering if the process of shrinking the VM, High Sierra "managing" that purgeable space, and Time Machine are stepping on each other.
This has happened to me THREE times now.
If I reclaim disk space, and *Time Machine automatic backups is checked in Time Machine preferences**, it will only take a moment to lock up the Mac host machine. It becomes completely unresponsive to any input.
I have to power it down and restart.
After restart:
1) The VM is corrupted
2) Running First Aid in Disk Utility returns an error in the file system; the file system has become corrupted.
3) Deleting and restoring from backup a copy of the VM does not work; The Mac will tell there is not enough space.
4) The only way to repair the Mac OS is to reinstall the OS and restore the entire system via Time Machine, then restore the previous copy of the VM.

My workaround is to manually uncheck "Back Up Automatically" then shrink the VM. I have never had an issue doing it this way.
The first 2 times I hadn't figured out what the issue was. The third time was when I forgot to turn of auto backups.

Has anyone else run into this?