I have the exact same issue with the back right print bed not adhering as well as the rest of the bed.
gr5 and yellowshark make some interesting points that I will also try.
Here are a couple of the things I've been doing:
1. Pre-heat the bed 5-10 minutes before I start the print. Based on yellowshark's comment I will probably increase this to 15 minutes.
2. Print a skirt. If the skirt prints OK, the rest of the print probably will too.
3. I watch the first layer and if I see trouble in the back right corner, I very slightly push up on the bed with my hand from underneath the print plate. I know this sounds crazy and dangerous, but it works for me.
I've experimented with different adhesives, but find printing directly to the glass to be the best. I clean and polish the glass and the prints stick very well, but pop off easily after it has cooled.