Thanks for the photos. Of the the two vias we can see on the second board you have two breakouts, and one very unreliable track to pad connection. I imagine the via near the "C4" text is also close to cutting the track off.
I also checked with one of the fabs I have used and for a .4 mm hole their standard service would require a .8 mm pad but .4/.6 is certainly available and may incur an extra charge, in fact they will do down to a 0.1 mm hole. The annular ring for .4/.6 is still twice the minimum required by IPC-2221.
But clearly this fab wasn't up to the task.