The pressure has nothing to do with it. Do you let the glue dry long enough before putting on the patch? It needs to look dry before putting on the patch. Do you sand the surface of the tube where the patch is going to go. Do you touch the sanded area with your fingers and leave oil from your skin on the tube? Done correctly patches don't fail. They don't fail later either. They work in any weather.

It's kind of funny, some of the assumptions on here. I just said I tossed the old tubes these days - I've probably applied hundreds of patches 40 years ago and most of them held up as I recall. I've had a handful of flats the last few years, mostly on the kids' or wife's bikes. When I don't feel like patching I use a new tube - a couple of bucks, what's the issue? The old one I might patch later, might cut up if I want a strip for some reason. I don't think I've actually thrown one in the garbage in two years. If anyone wants to keep patching the same tube more power to them. To me, that's throwing good time and money after bad but like I said it's still just a couple of bucks.

I bring a spare tube with me, so I can replace it on the go if necessary. When I get home, I patch the one I just replaced, and it becomes my replacement to carry with me.

In my experience, glueless patches are a waste of time if you're running over 50 psi

Never tried a glueless patch, but the normal ones work forever, if they're done right. I keep patching until the valve stem fails.