Unable to find and link JIRA ticket Edited

[Azraai Baharin]

1. When adding JIRA macro, and trying to search for ticket, it returns "Received the following HTTP error code from the server: 200"

2. When adding a JIRA link, it gets converted to the JIRA macro, upon saving the updated page, the JIRA link is unable to display the details but instead displays the text: "java.io.IOException: Error on line 78: The entity name must immediately follow the '&' in the entity reference."

3. The following error is found in atlassian-confluence.log:

Caused by: java.io.IOException: Error on line 78: The entity name must immediately follow the '&' in the entity reference.
at com.atlassian.confluence.extra.jira.request.JiraChannelResponseHandler.getChannelElement(JiraChannelResponseHandler.java:48)
at com.atlassian.confluence.extra.jira.JiraIssuesManager$ByteStreamBasedSupplier.get(JiraIssuesManager.java:138)

4. Versions:
Confluence 7.6.2
Jira v8.8.0

5. The application links status both in JIRA and Confluence are "CONNECTED" with the outgoing and incoming connections set as "OAuth (impersonation)". 

6. Same display is observed if using other user with the same permissions.

[Jan-Peter Rusch]

We're also affected with a similar message, if a user is not logged into Jira.

2020-09-11 08:57:10,758 ERROR [JIM Marshaller:thread-291] [extra.jira.request.JiraChannelResponseHandler] getChannelElement Error while trying to assemble the issues returned in XML format: Error on line 4: The entity name must immediately follow the '&' in the entity reference.
-- url: /confluence/display/SPACE/PAGENAME| traceId: f74f25314edcf420 | userName: xxx | page: 470451431 | action: viewpage

[Justin Kamerman]

Any resolution to this?
having exact same issue with exact same versions...

[Justin Kamerman]

found a solution to this:
for us it was the 2FA app on jira causing this.
When i disabled it .. it allowed the info to pass from jira to confluence.
So for a proper fix.. i added our jira group name into the app white list feature.
Working well now.

[Jan-Peter Rusch]

Doesn't solve the problem on my side. I disabled our 2FA app (SecSign) on both systems (Confluence & Jira). The issue still persists.

[Azraai Baharin]

Yup, it is the same case for us too; JIRA's 2FA plugin. But we are struggling to whitelist our confluence based on IP (due to the nature in which we deploy it). 

May I know what do you mean by "added our jira group name into the app white list feature"?