Is this moisture on the outside or the inside? Can it simply be wiped off with at stroke of a soft cloth, when the condition arises?
If it is the outside, I’ve read that some people have had success with rainx, not that I really know what that is, but people have reported success. YMMV. Not sure how it could differ from Ring, from a quality perspective, in this regard. If it is the outside it’s more likely to be a difference in mounting method and position that causes the difference, as a result of warmth being passed permanently from the building to a Ring doorbell.
I haven’t had this experience from any of 5 externally mounted XTs. One is in an extremely rainy part of the UK, and 20 feet up a tree, so it’s always damp, but never any fogging. Well, actually that’s not true, if I check it when it’s pouring down, and the wind is blowing directly at it, I can’t see anything for drips running down the camera lens, but still, it’s never fogged, as such.
If it’s inside, and doesn’t wipe off, then maybe your seal is damaged, or you sealed it up on a very wet day. Inspect the seal very carefully, because if not damaged it will operate as designed. Obviously if it is inside the camera you will need to dry it all out, before sealing it up again. If the seal is intact, and you’re sure it’s now dry, add a little silicone to the seal, just a wipe around, and seal it up in a non humid and temperate atmosphere. If you do this I’m sure you will be fine in future.
If it’s outside, then that’s just science, and will affect anything where the temperature changes quickly, with high humidity. Nothing you can do about that. Ever been out to your car just after dusk, or before dawn, and seen it covered in drops, or the grass in your yard covered in dew? I’d like to hear how Ring are avoiding that.
As I mentioned, others have suggested rainx can help though.
As for the difference between Ring and Blink, if it is outside condensation, how can there be a difference?