Is this a failed DWV test?

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Aug 25, 2021
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Code states that 5# of pressure must be held for 15 minutes for a DWV waste line.

The pipe underneath my slab has already been tested and passed in February 2021 by the city building inspector. Fast forward about about six months and the rest of the DWV system has been tied into the lines underneath the slab. I pressure tested the entire system and after fifteen minutes it dropped to 4#.

Now, I believe the leak is coming from the portion of the DWV underneath the slab BECAUSE....I have tested every joint about the slab and have found no leaks. This situation has me pulling my hair out by the roots in handfuls.

When I opened my grinder pump I noticed there was about twenty gallons of water in the basin. The water was dripping very very slowly from the DWV line. Thus I figure that there is a break in that aforementioned passed DWV line and the water underneath the slab is making its way into a crack in the DWV line. (OR maybe its soooo humid in this area the lines are condensing on the inside?)

Would this pass a leak test? (probably not)
What would you do to figure out where the leak was coming from?

Thanks in advance for any ideas.