Update on the 7850 front wheel:

I installed the correct Shimano front valve which does seal better than the generic ones I had been trying.

But it still does not allow my Hutchinson Atom tire to mount.

I had been holding out and not taking it to the LBS thinking that I could resolve the issue.

But today I took it to the LBS & they were unable to get the tubeless tire to inflate.

So he removed the tire & looked carefully @ the rim and it turns out that the interior rim shelf has a 2” crack in it!

He suggested I photograph it and send a picture to Shimano & see if they can do anything for me.

in the meantime he said to put one layer of tubeless tape to cover the rim crack & see if this allows the tire to mount & hold air.

if anyone knows the process for contacting Shimano -i’d Like to know...