Contact official RICOH customer support.
https://support.theta360.com/en/contact/
It appears that something is wrong with the lens, either some type of oil coating or the lens itself. You can take a standard DNG shot (not bracketed) and see if a single DNG has clear views on both lenses. If not, you need to look into a return under warranty or through the seller (like Amazon).
You should be able to easily find DNG shots online from the Z1 to compare with your shot.
If you can’t find shots for comparison, I took some DNG shots for technical tests. I just walked around a store without planning any of the shots. You can see that each sphere is clear.
THETA Z1 Sample DNG RAW Images
You can also download the files and compare them to your own files. Other people likely have better files, but these are straight from the camera with default auto settings.