The trick that works reliably for me, had to do it just 2 weeks ago in fact, is dish soap as a lubricant between the rim and tire.
You have to let almost all the air out. Squirt some liquid dish soap on the tire just above the rim, then with a finger spread that down into the interface between the tire bead and the inner wall of the rim. Doesn't need much, but enough to get an even film all the way around. Flip the wheel and do the other side.

Unless the tire has a kink in the bead, from manufacturing defect or it got damaged somehow, this allows the tire to move to the place it wants to be, which is the same height relative to the rim everywhere. Still I wear ear protection in case it blows off the rim, but I have never done that despite working in bike shops for 30 years. I've been there when the next mechanic over did it, without warning anyone, and my hearing is probably worse thanks to those yayhoos, and I'm extra careful about hearing nowadays. Inflate until you hear the wonderful pop sounds the tire makes as it snaps into place.

After the tire is inflated you can wash the dish soap off the tire and rim. Of course some remains down in the tight interface, but that doesn't harm anything.

EDIT:
My bad, I missed the part where you said "The bead seat line is has the same space all away around the rim.". The dish soap technique probably won't help in that case, that's just a bad tire. Sorry to be a time-waster.