row selection not working for grouped rows (flat data)

[csantos-nydig]

Describe the bug

row-selection in the group rows are not correctly reacting to their sub-rows row-selection state

I'm not sure if it's the same issue as #4878 - but better to track separately.

Your minimal, reproducible example

https://codesandbox.io/s/row-grouping-8twj0x

Steps to reproduce

1. Go to https://codesandbox.io/s/row-grouping-8twj0x
2. Expand "relationship" group
3. Select the first child in that group
4. ✅ Notice the "relationship" group being "indeterminate"
   
5. Select the other 2 children in that group
6. 🛑 Notice the "relationship" row checkbox is "unchecked", when it should be "checked"
   

Possibly the same issue

1. Go to the same codesandbox https://codesandbox.io/s/row-grouping-8twj0x
2. Expand the two groups
3. Select the checkbox from the column header (to select all)
4. 🛑 Notice the parent row checkboxes aren't checked
   

Expected behavior

As a user, I expected the parent row to react to the row-selection status of its children, regardless on how they are selected/unselected:

• some sub-rows selected: parent row "indeterminate"
• no sub-rows selected: parent row "unchecked"
• all sub-rows selected: parent row "checked"

How often does this bug happen?

Every time

Screenshots or Videos

No response

Platform

• Browser: All
• OS: All

Happens in codesandbox

react-table version

v8.9.1

TypeScript version

N/A - whatever codesandbox uses

Additional context

No response

Terms & Code of Conduct

• I agree to follow this project's Code of Conduct
• I understand that if my bug cannot be reliable reproduced in a debuggable environment, it will probably not be fixed and this issue may even be closed.

[VincEnterprise]

bump