JIRA Pie Chart does not display values from Tempo's Account field correctly

Issue Summary

JIRA Pie Chart does not display values from Tempo's Account field correctly

Environment

JIRA 8.1
Tempo 10.2.0

Steps to Reproduce

1. Add an account in Tempo Account configuration, link it to a project
2. Open any issue from the project and set a value for the account field
3. Add a pie chart with a filter/project that includes the issue above and select the Account field as "Statistic Type"

Expected Results

Accounts are listed correctly (in 7.x)

Actual Results

Accounts are not listed, instead all the issues are grouped under "none"

Notes

This works fine in JIRA 7.x, with latest compatible Tempo version 9.4.2

Workaround

N/A