Vivarium Electronics is RBI but sounds like their manufacturer in China is messing up the forming process. Not sure if Pangea is using the same factory as RBI but might want to give them a try as they are the same structure but might just now be resold by pangea so might not work.
The slickness is a non stick lubricant used in the injection molding process and the warping is due to removing the product from the form too quick and not letting the structure align properly. This is 100& due to the factory that RBI is outsourcing them from. You can report this to them if you want.