Thanks for the info - it is now fixed and published
Fortunately, the bug was cosmetic (for updating node status) so operationally, there was no problem.
PS, your test flow can be simplified to this (apologies if i'm teaching you to suck eggs)...
[{"id":"bcda75bf.c394a8","type":"inject","z":"21106466.70e60c","name":"remove-all","topic":"remove-all","payload":"true","payloadType":"bool","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":980,"y":280,"wires":[["a2299126.371a3"]]},{"id":"a2299126.371a3","type":"cronplus","z":"21106466.70e60c","name":"","outputField":"payload","timeZone":"","persistDynamic":true,"commandResponseMsgOutput":"output1","outputs":1,"options":[],"x":1200,"y":280,"wires":[["9aacf955.869d18"]]},{"id":"b4d98f36.29cea","type":"inject","z":"21106466.70e60c","name":"add 2 schedules","topic":"","payload":"[{\"command\":\"add\",\"name\":\"every 6\",\"expression\":\"*/6 * * * * * *\",\"expressionType\":\"cron\",\"payloadType\":\"default\",\"limit\":3},{\"command\":\"add\",\"name\":\"alarm1\",\"expressionType\":\"solar\",\"solarType\":\"selected\",\"solarEvents\":\"sunset\",\"location\":\"54.999320540937035 -1.417407989501953\",\"offset\":\"-60\",\"payloadType\":\"str\",\"payload\":\"In 60 mins, it will be a great time to take photographs\",\"limit\":null}]","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":1000,"y":240,"wires":[["a2299126.371a3"]]},{"id":"85038c59.6f9e3","type":"inject","z":"21106466.70e60c","name":"status-all","topic":"status-all","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":980,"y":320,"wires":[["a2299126.371a3"]]},{"id":"9aacf955.869d18","type":"debug","z":"21106466.70e60c","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":1330,"y":280,"wires":[]}]