Skaffan, do not jump just yet. you already have the Visa, great if not, then confirm with the authorities. As you say, you have an unlimited contract since Apr17, I am not sure, but I think unlimited contract means you have to complete 5 years with your current sponsor.
Also, if you scan post in the past month, you will find, one person had a job in the private sector and got a job in the public sector, however, he could not take the public sector job as it can be done by a local. so basically he jumped into fire.