I apologize for my previous misleading message. Indeed, we recently made a decision about New language features now available exclusively in latest SonarQube versions, which applies for the ongoing LTS as well.
Can you please try with S4487 in addition to S1144 (it’s a similar rule)? I suspect this is the culprit.
If that doesn’t work, try disabling S3655, S3966, S3900 or S1944? Another idea would be S1128 (unused usings).
Please let me know which of these rules are the culprit. Because your analysis doesn’t end, this is the only way to see the rule with the problem.
When you’ll tell us what rule has the problem, we can take a decision whether to patch the LTS or not. Thank you.