Upon rule execution custom Multi-picker user field will not get populated with users if users become inactive

Issue Summary

This is reproducible on Data Center: Yes

Steps to Reproduce

1. Create a custom multi-picker user field and associate it with the project of choice
2. Add the customfield to any one of the project issues ( Ex - SCM-01 ), and select two users of choice (testuser, testuser2) in the customfield multi-picker user fields
3. Go to Project settings -> Project Automation
4. Create an automation rule for the trigger "Issue created"
5. Set New action as "Edit issue fields" and for customfield copy the data from the parent - shown below
   
6. Now, go to issue SCM-01 and create a subtask for the issue, this will trigger the automation rule and the subtasks will contain the same customfield with users copied from the parent issue.
7. Next, go to System->User Management, and make one of the users inactive (testuser).
8. Go to issue SCM-01 and create another subtask for the issue, this time the subtasks won't contain the customfield added to the issue. 

Expected Results

Functionality was working fine for Jira 7 :-

Test jira7 customfield contains the same set of users in subtask as in parent, as shown below

This feature is not working for Jira 8 and Jira 9 versions

checked on 8.21 and Jira 9.4 versions

Actual Results

Below screenshot shows the subtask missing customfield

Audit log shows error:-

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available