Hi,
Based on your description there are three possibilities:
1. Your log location is different from the default log location for Adobe campaign
2. you are not using syslogd for logs. By default, the Adobe Campaign platform has the syslogd module installed on it, but it is possible to use another syslog daemon. This module creates the log files in the log directory. If you had any build or infra updates this might have happened.
3. Somehow your web.log creation is disabled.
Follow this step to ensure that you are actually generating logs in the default location:
use a file/Js activity in workflow and test if you have a web.log file in the given directory
<installation directory> /var/default/log/
if you do not have this file raise a Support ticket and they will be able to fix it for you.
If on-premise then reach out to your support admin.
regards,
Amit