Swollen salivary glands it sounds like, specifically the sublingual gland. 2C-X compounds have been known to apparently influence the immune system and give people phlegm and mucus production. I wouldn't be surprised if the 25-X compounds can do similar things even though I never heard of this specific reaction. Mouth ulcers, I assume like aphthous ulcers are not that well understood but are associated with immunological resistence so yeah I guess it caused some disruptions.
Chemical burns in cases like this present as irritation of the mucous membranes so you would expect redness and some pain. I don't think swelling and ulcers are quite the same thing, but they don't have to be mutually exclusive either.
Probably still minor though but not very comforting to have novel drugs do this to your body...
You administered it sublingually?