Hi,
from in the received messages about daily changes "lfd on ....: Excessive resource usage: clamupdate", I see the following:
Time: Sun Sep 1 14:02:35 2019 +0300
Account: clamupdate
Resource: RSS Memory Size
Exceeded: 424 > 256 (MB)
Executable: /usr/bin/freshclam
Command Line: /usr/bin/freshclam --quiet
PID: 31455 (Parent PID:31454)
Killed: No
Thank you in advance and ask for your assistance ....
BR
Venty