You might want to also put a little Toyota Red 1281 FIPG at the inner retainer connection to the axle. Once you've determined you have a good mating of the axle seal with the inner retainer by doing the sharpie test, I'd clean up the axle and retainer well with some brake cleaner. Then I'd smear some FIPG on the inside side of the retainer to axle connection and let it dry for a while. Gear oil can get past through 3 areas, between the inner retainer and axle seal connection, between the seal and axle housing connection, and between the retainer and axle shaft connection. If you have a good mating of the inner retainer and seal, and you've used FIPG at the two metal to metal connections (seal to axle housing and retainer to axle shaft), you've eliminated any potential for gear oil to get past and to infiltrate the bearing.

Now, why do some people have to use FIPG at these metal to metal connections and other don't. One reason is maybe there's some imperfections in the metal, like somebody used a hooked seal removal tool and they gouged the axle housing. Another reason is reusing retainers. I thought this was a good money saving idea at first, but then I realized some damage happens to the retainer when you press it off the axle. Metal is lost during the removal and there are noticeable grooves left on the inside of the retainer. This ends up being a pathway for gear oil to get past the retainer/seal connection. I now instruct people to use a new retainer at the inner position, but they can definitely reuse an old retainer for the outer position because that is just a place holder for the bearing.

Good luck with getting the leak to stop and you can put this repair to rest.