This reminds me of some very direct posts a little while back on the forum and for some reason it's crickets now...
Quoted from rubberducks:They're using cheap, soft, un-aged wood and don't appear to be allowing adequate drying and hardening time for the clear either.
Quoted from rubberducks:The wood is too young, too soft, too coarse, and ultimately too prone to warping.
Quoted from rubberducks:The inserts are sinking or popping up because the wood is too young and too soft.
Quoted from rubberducks:No it is not speculation.