Calculated Column is incorrectly not rendered when spanning multiple columns

[BroCode23]

Describe the bug

When using a datagrid that includes frozen columns and multiple spanning columns, when selecting the first set of spanning columns and scrolling, the second set of spanning columns are hidden

To Reproduce

1. shrink the window to ~850 px wide
2. click on the header cell containing '8'
3. scroll to the right on the datagrid until the '16' header cell disappears

Link to code example:
BugTest.txt

Expected behavior

the spanned column should remain visible when part of it is hidden behind the frozen columns

Environment

• react-data-grid version: all versions
• react/react-dom version: all versions

Additional context