I get ashtray-mouth from time to time. Not pleasant. Seems like sometimes it's the Ecuadorian CT wrapper, or the combo of CT wrapper and Nic. filler -- got the exact same thing from the Perdomo Reserve 10th Anniv. Champagne Series and the Roma Craft Intemperance EC XVIII -- and sometimes happens either when the draw is too tight, so I'm huffing and puffing and it gets overly-hot, or counter-intuitively, when the draw is too open and it gets hot no matter how slow my cadence is. I realize this is heresy, but that's my one gripe with Padron Delicias -- I think the draw is too loose and the tobacco gets charred (as opposed to the Londres, which seems to have a reliably perfect draw and flavor).
That being said, I didn't have that particular issue with the Olvia CT petit corona, but I did find the mustard-like greenish-yellow color of its wrapper to be weirdly off-putting.