[Xymon] ext script does not run on client restart

Hi

I have an ext script to check for the status of available patches on my hosts. Once I have updated the patches, I restart the xymon-client so that the test will go green again. Occasionally the ext script will not run on restart. Is there a way I can debug what the xymon client is choosing to run? How does xymon track the interval after a restart? My clientlaunch fragment looks like:

[patches] ENVFILE $XYMONCLIENTHOME/etc/xymonclient.cfg CMD $XYMONCLIENTHOME/ext/hobbit-patch.sh LOGFILE $XYMONCLIENTHOME/logs/hobbit-patch.sh INTERVAL 6h

Client version:

ii xymon-client 4.3.17-6+deb8u1 amd64
client for the Xymon network monitor

Thanks for any advice!

Iain