Tire slips off the rim when inflated to 8bar
Especially when seating a new tire for the first time (and probably more so on a "virgin" rim) it's wise to inflate to about 1/3 or 1/2 final pressure and then roll/bounce the wheel around quite a bit, to work the bead into position.  Then deflate, break the bead loose all around, and repeat the process.

Then, as you're doing the final inflation, watch the joint between tire and rim all around.  Usually there will be ribs in the side of the tire that should be a constant distance from the rim.  If you see the ribs moving up or down relative to the rim, stop inflating and manually work that section of tire back even.

Generally once the tire has been ridden a few miles it takes a "set" and will then reseat relatively easily if you have to repair the tube.

But do note that there are variations in tires and rims, some due to spec differences and some due to manufacturer differences.  It's possible in several scenarios to have a tire and rim that are simply not compatible.