issue_field_value_append - TypeError - concate list to string

[Cybernetic-Ransomware]

When creating a new value, line 1359 attempts to concatenate a string value with a list containing one new proposed value:
new_value = current_value + [value]

This results in the following error:
TypeError: can only concatenate str (not "list") to str

When I only replace the custom field value, the user's permissions to view and edit the issue are sufficient. However, after addressing the error above, when I attempt to append a new line to the custom field, I must use two methods: Jira.issue_field_value and Jira.update_issue_field. Surprisingly, using the first method (a read-only operation) requires administrator permissions.

Is there a guide or best practice to limit the elevated privileges required for a user to call these two methods? It seems inconsistent that a read-only method demands administrator permissions.

Source file:
https://github.com/atlassian-api/atlassian-python-api/blob/master/atlassian/jira.py#L1359