What do you mean the tire isn't "tight". Do you mean it's still soft? or that the super high pressure didn't seat it.

I suspect that what's happening is that the valve is sticking and your pump is reading hose pressure, not tire pressure.

The possible causes are that you failed to back off the nut far enough, your pump head isn't pressed on far enough, or the valve is a bit sticky and you didn't press it before pumping to make sure it's free.

The last is usually only a problem when topping off tires that already have high pressure in them. I've been using Presta valves for over 40 years, and never ran into this until fairly recently. I suspect that the Taiwanese tube makers are using valves with a softer seats than those used by the Italians (but that's just a guess.

These days I can still top off my tubulars the way I always did, but have to "burp" the Presta valves in my commuter first.