It is very obvious.
When you installed them, the pipes got kinked. It is preventing the water from flowing.
Hope you can still access it. It is not ceramic tiled yet, I guess?
Then, take it out, buy a new braided connector. It does not kink.
This is the only way I can think of.
It is simple: water just ain't flowing. If you are confident of your installation, then the valve seat or the cartridge you put in (for washerless faucets) is not installed correctly. This is where I will look first if I were you. The way to tell is to see whether the handle turns smoothly. It has to be really smooth. Otherwise, you have valve seat or cartridge problem.
Valve seats stays down under water pressure and it does not open when you turn the handle. This is common. If you have tightened the nut (just below the handle) too much, then the valve stem is bent. Replace.