This answer from Oct '18 (nearly 2 years ago as of today, Sept 18, 2020) just showed up in the review queue as "Potentially low quality because of its length and content."
For 2 years, it's been just fine. Have there been system changes that are impacting how the system sees answers and it's being applied retroactively and not just to new content?
Granted, I asked a question about it when it was originally posted, and the OP never responded, but that doesn't mean it's low quality, it just needs a bit more info.