New engine has loss of compression

It's more common than you think but not fatal. Not the first time I've heard of it, but out of around 10 sets over the past 12 years I've never seen it myself. I have had incorrect valve springs (like 1 out of 16) before, and no valve seals before in addition to the terrible finish and valve jobs. There should be cups under the shims to keep them from eating into the aluminum head.