Hi there,
Good to hear from you again!
I'm glad that you have found a correct solution for your previous issue.
This time it actually looks like a bug, so feel free to report it on our GitHub Issues page, and wait for any fixes/workarounds there.
Alternatively, play around with the dataLabels formatter, maybe there is some custom formatting that might be causing this little bug?
GitHub Issues: https://github.com/highcharts/highcharts/issues
Thank you for your patience,
Best regards!