New JLC running out of spec

I have recently acquired a new JLC, but the accurancy is basically all over the place.
It was running minus -15 sec after a day, the next day picked it up was running plus again, end of the day was minus again.

I thought with the 1000 hour control this should not happen?

Can this be due to the settling down and starting up of the watch, or should i have a different pattern there? What would be considered normal deviation in the starting up phase?

My first JLC and i did not encouter this with all of my other watches.

Thanks in advance for the advice.