Vibration in front-end

[A//// Guy]

Im guessing the rubber stuff they sealed the wheel/tire with maybe the cause? Take the wheel that has the problem off, replace it with one of your winter tire/wheels, and see if the problem persists. Its odd because the problems come and go and while coasting seem to disappear and reappear?

Sounds like a balance issue and maybe the rubber stuff they sealed the rim with is liquid and messed up balance in the rim as it was drying? Start with replacing that wheel and if it goes away thats the cause.