Crank seal leak - installation question

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Hey guys!

TLDR version. I've replaced a right side leaking crank seal with a new one and replaced an o'ring behind it on a crank shaft. After placing everything back on the crank and tightening the nut at the top of the crank shaft drive gear I ve reperformed the leak down test and the seal appear to leak even worse than before.... What may cause that?

Long version :

I am new to two strokes and got myself a 2014 ec300r used sometime ago. After inspecting a spark plug it looked like bike was running very reach and was really hard to start. Needed like 20 kicks at least. So I figured I would check condition of the top end after making sure that the bike has a spark and clear air ways.
Bike happened to have a brand new top end although previous owner didn't mentioned that. I ve checked the bore size and a piston with the rings and everything is well within specs.
After cleaning a power valve which were heavily carbonized (the valve actually couldn't move in full range since one of the ridges that goes across the valve and host ones of the rods had so much carbon that it blocked the rod from moving in the full range. Anyways after making sure that top end is in a good order I scouted this forum for other potential issues and decided to do a leak down test that is recommended in many other cases.
So after installing a leak tester I got it 6psi and were losing about 2 psi in 5 min which I guess is not too bad. It took me a while to locate the leaking point at the clutch side of the engine really close to the frame at foot peg level. So my immediate suspect was the crank seal, which seems to be one of the common leak points.
After getting to the crank seal while fighting a rusty pin by the water pump to to get the cover along the way, I ve managed to plug the power valve outlet and redo the leak down test to reconfirm that the crank seal is actually leaking which it was. So I ve proceed to a tedious seal extraction process which involved taking off a crank nut by jamming a cylinder with a rope through a spark plug hole and a lot of cursing followed by drilling and tapping an old seal with a wood screw to extract it.
Then it was time to get the new seal in which really didn't want to get into place so I had to heat up the area and slowly tap it in place. While doing so I didn't realize that the slider that is mounted on the crank and slides on the inside of the oil seal and the little metal bump key is on the crank that holds that slider are actually removable. Anyways after realizing that I took the key and slider behind it off to access the o ring that sits at the base of the crank shaft bearing to replace that as well.
After that it was time to get everything back together, so I thought to double check the new seal with a leak down to make sure that it works... And it was worse... Way worse than before. The new seal was leaking between it's rubber part and the slider in several places. So I took everything off the crank shaft again to double check if I am missing anything or damaged the seal or the slider which both looked OK to me with no damage.
Now the bike is just sitting and driving me crazy. I have cleaned, assembled and leak tested that thing for several times and it keeps loosing air sometimes more sometimes less and most of the time in multiple different places around where slider connects with the rubber part of the seal.
So is there something I am missing or have I damaged something during installation? I suspect that while extracting the old seal I may have poked the rubber on the bearing behind it but it looks that I scuffed it rather than made a through hole. Also I think if I've damaged the seal while installing it onto the hot slider and the crank shaft housing... Or maybe I leave some tiny debris between the seal and the slider and that makes it fail.... Although I tried to wipe everything and apply assembly lube every time I tried to make it work.
Anyways I am a bit desperate now and would appreciate any thoughts on what may be the issue here.

Thanks!