Yes I understand they are not linked I just put those screenshots because they are easy traces to show.
I tried to look at full log file and noticed a few things that may help to understand or figure out why it did not work.
First camera lost event is 00:54:36 then HTTP call triggered at 00:56:51 so this is 2m15s after first DeviceLost event that is much more than 30 seconds (don't want to be finical I don't really care if it trigger 30s or 1min later, but may be this is important for you to know it did not trigger after 30s as you said).
Before the HTTP call the events showed a loop of two lines (I did a copy/paste into excel to move the time column to the left because having a log with the timestamp not being the first column is a bit unusual).
Then came the Rule trigger
Note that the called rule produced en error as I changed IP of the camera from .20 to .69 and forgot to change the HTTP call parameter so this error is "normal" and it's on me but I didn't noticed it immédiately.
Then the event log changed a bit adding "WakeUp" events in the loop
Once I noticed I made a mistake in the HTTP parameter I fixed it but however the HTTP call never played again so I restarted the RTSP server inside camera manually.
So question is, is it normal the HTTP call triggered only once ? is it because it returned an Error that it stopped trying again later or should it have retried later anyway (whenever it is not the case here befeore it was a "real" error due to bad parameter, it could be temporary error so it should retry anyway every xx seconds) ?