Material extruded to prime the nozzle doesn't stick to bed at first
Have you tried using a raft

I had the same issue on my mini delta when I first started printing with it. After checking and double checking the bed level I ended up discovering that using a raft base in Cura solved the issue.

It does use more plastic however I have had absolutely no issues with respect to sticking in the dozen or so prints since then. 

Additionally it makes removing the print from the bed really easy as I'm not worried about damaging the print with a scraper.