This was the patch from the other day, Park brand.

Note that the other 3 corners had the same creeping failure, but I pressed on the patch which appears to have re-bonded those failed areas.
Notice also that the tube was buffed fully to flat black, down to the rubber, and that the freshly-peeled patch was repeatedly pressed on with real pressure.

The failures all started at the corners and worked towards the hole, which was not as big of a hole as appears here. A complete failure with air loss did not yet occur, yet from past experience I decided to have a look.
Tugging at one of the corners that I pressed back down shows that a re-bonding has occurred, yet the adhesion doesn't hold up to being inflated in the tire for a few hours.

Note also that this tube measures 26mm wide in a flattened state, fitted into a tire that was nearly, but not quite 27mm inflated width. This is a very normal, middle-of-the-road width ratio for high-performance road bike tubes/tires.

But this is all BS, I'm from the stupid generation, I wiped my forehead with the sticky side of the patch, blah, blah, blah.