Euphorbia Obesa help

[WallyD]

I got this plant maybe 3 weeks ago and it sits in full sun and warm temps (highs low 80sF lowest is mid 60sF. zone 11a by the ocean). Watered him twice,once every week, but no other water. Noticed that it has some of the white euphorbia sap coming out of a tiny spot...not sure why. It's on a protected patio and was set behind other plants safely, so no birds around here to attack it.

I read somewhere that they can do this if too much sun/heat, but I'm not sure. Never had a euphorbia do this before. Not going to touch it since I know the sap is poisonous, but any ideas on what the problem might be? Thanks in advance for any help.

[Worm]

It's likely not a symptom of rot or disease, at worst a bug bite? Once a week watering is plenty for an Obesa, perhaps as it expanded to absorb that water an old scar reopened.