Custom storage does not refresh to reflect changes

[TJ]

20.04.1, Custom storage layout

This view does not refresh when underlying changes have occurred, whether using the "Reset" option, or using 'Back' to move back through the pages.

Specific scenario is related to "Unable to add a GPT partition with 400+GB free space" bug #1901478

After using Help > Root Shell and using gdisk to create a partition with the free space, and ensuring the kernel's view of the device is updated (confirmed via /proc/partitions), there appears no way to cause the installer to refresh its information and therefore it continues to report only 4 partitions and 400GB free space when there are 5 partitions and 0 free space!