I'm using Repetier and Slic3r and it is printing a gap between the perimeter and infill on the first layer. Also, the infill is lifting (as in photo). Any advise?
You're not sticking to your bed. Adjust your bed height. You are too far. Otherwise you are going too fast and or too hot.
Calibrate the bed. Reduce speed. Then adjust temps.
Also could be material contamination
See this link for a visual troubleshooting.
In addition use some gluestick. That will often solve these issues. Last but not least add a raft if it continues. Or just ignore it. My bet is temp is too hot. I also like to smash my first layer, but not everyone likes that technique as it causes elephant footing.
I was having these issues too on a CR-10S and I worked on it for months and the only thing that would fix it was the spread, overlap, and width of the extrusion, this may also be caused by the fact that I haven't really tried to use glue stick or anything to get my prints to stick better.
I found a solution that works for me.
I have increased my first layer extrusion width to 250 %, reduced the print speed of perimeters to 30 mm/s, reduced the brim width to 1 and increased the infill/perimeter overlap to 30 %.
This was PLA with heat bed off (no heating), printing on glass and using hairspray as an adhesive. Most of my settings were on default. (Repetier & Slic3r).