It seems that log rotation does not work: there are some logs with the size exceeded the one allowed in the log rotation settings Websites & Domains > Logs > Log Rotation .
Such situation is possible, it does not mean that log rotation does not work correctly.
If the log rotation condition is set as size Plesk rotates logs when their size exceeds a particular limit, the log rotation is being triggered by the Daily Maintenance script. So if the size of log file exceeds a particular limit but the Daily Maintenance is not started yet that log file is not being rotated (until Daily Maintenance).
To get additional information regarding log rotation please refer to Advanced Administration Guide, Plesk for Linux, Log Rotation .