After upgrading to version 11.8.2, the ws-legacy.log configured the size limit and is not rolling over. The maximum size is set correctly in general.properties as follows:

appender.rolling.policies.size.size=10MB

The ws-api.log and the ws.log do not have the problem. Their maximum size corresponds to the configuration. In this case, 10 MB.

This issue no longer happens in version 11.8.3. Please upgrade to this version.

The workaround is to stop the WorldServer (Idiom) Service and remove the ws-legacy.log file or zip it if you want to keep a copy, and remove the original one. 
Then restart the WorldServer (Idiom) service. A new ws-legacy-log file will be created.

Relevant article:

WorldServer: How do I control the maximum size of my WorldServer log files visible in my System Logs page?