My automation (below) is unsuccessful in trying to set Business Analyst from Development Manager ({ssue.Development Manager.displayName}} and QA Resource from reporter ((issue.reporter.displayName}} in edit actions. A log action prior to the actions shows values for both source fields.
Perhaps not coincidentally, there is an exclamation point displayed after the rule, that I think indicates an undefined issue. I tried adding a couple of refresh actions, but there was no change in the result.
Rule

Rule log
[The page couldn't load, suddenly]
The log actions showed no values for the two fields, after the field edit actions. I'll post the log after the page load problem is resolved.