After installing a new shower valve in a new bathroom I turned on the water. The lines initially held up to the initial pressure but after a min or two a very slow drip was noted around where the 1/2 male connectors enter the valve on both cold and hot water sides. I’m using pex B to connect all the water as well. Curious if anyone has an idea as to why it’s leaking. I used tape on the threads prior to installing as well.

not tight enough.

It won’t take a full again to be on the correct angle to run the pex down the wall. It’ll only take a quarter turn at best which makes it face horizontal instead of vertical.

The adapters may have been installed TOO tight which will also cause a leak.

Remove them, retape/dope them, install again looking for 4-6 complete turns.

Do NOT 'back off' when 'aiming'.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

The slow drip around the 1/2 male connectors entering the shower valve could be due to a few potential reasons:
1. Improper tightening
2. Faulty or damaged connectors
3. Insufficient sealing
4. PEX connection issues
If the issue persists after double-checking these aspects, it may be worth consulting a professional plumber.