Deleting issues, LexoRank Balancing and Issues in Epic do not render

[Boris Link]

We are encountering multiple errors in Jira 8.7 hosted on our server:

1. Can't delete issue

https://community.atlassian.com/t5/Jira-Software-questions/Cannot-delete-issue-LexoRank-Related/qaq-p/1057358

When I try to apply the proposed fix https://confluence.atlassian.com/jirakb/remove-duplicate-rank-fields-in-jira-server-779159223.html?_ga=2.194018477.163707424.1584962666-1047052085.1584704350

And run step one: I only get: 10005 in return, so there don't seem to be duplicate Rank fields.

2. Issues in epic do not render:
https://confluence.atlassian.com/jirakb/issue-screen-displays-error-rendering-greenhopper-epics-issue-web-panel-in-jira-server-779158857.html

When I run the proposed Select:

SELECT * FROM issuelink  il
WHERE il.LINKTYPE =
  ( SELECT id FROM issuelinktype WHERE linkname = 'Epic-Story Link') 
AND
(
  il.destination IS NULL
  OR il.SOURCE IS NULL
  OR not exists (SELECT null FROM jiraissue ji where ji.id = il.destination) 
  OR not exists (SELECT null FROM jiraissue ji where ji.id = il.source) 
);

No issues are found.

3. Balancing in LexoRankManagement doesn't even show up.

And the proposed fix: 

https://confluence.atlassian.com/jirakb/how-to-fix-duplicate-rank-values-for-a-rank-field-779159224.html

with PUT doesn't solve the issue and creates this output:

Expected to find one rank row, but found 0 rows

Any suggestions and if you need further details, please ask for it and I will provide them as best as I can.