I understand very much what your not understanding. i"ve gone through the very same thing when using lucee for the first time. The problem is you are cross referencing webcontextes. I’ll try to do my best to explain it:
Every Domain you use in Lucee runs in different context. As I can see you are running the webadmin in:
http://127.0.0.1 (webroot would by something like lucee/webapps/root)
and in the scheduled task you are requesting a URL of a page outside (in another context):
http://l.tchguard.com (webroot can be elsewhere, e.g. inetpub/wwwroot/)
The schedulers will be listed:
for 127.0.0.1 in lucee\webapps\ROOT\WEB-INF\lucee\scheduler\scheduler.xml
but you are running urls in l.tchguard.com, that would be inetpub/wwwroot/WEB-INF\lucee\scheduler\scheduler.xml
In other words: Becaue schedules are bound to the context you won’t be able to change the scheduler of 127.0.0.1 running a page and using cfschedule in a scrip within l.tchguard.com.
You are trying to interact by cfschedule from one context to the other. That means that any cfschedule command you run inside l.tchguard.com, will not be able to add/change/delete any other schedule of 127.0.0.1. It will add/update/delete only schedules inside l.tchguard.com. You will have to stick inside the same context when trying to change schedules with cfschedule
Hope that helps a little bit.