We stopped using the plug about 15 years ago at the shop for exactly that reason, couldn’t guarantee a proper repair. We use plug/patches now but requires the tire to be removed from wheel. I would try and ream out the plug and try it again with a lot of cement as you mentioned. Your in Cali so I wouldn’t think temperature would be a factor in the cement curing?Also if the hole is close to the edge of the tread, close to the sidewall, it will never seal correctly because of the flexing.RJ
