I finally got the gsi's to boot I ended up having to flash this as encryption of the data partition wasn't playing nicely with any gsi's. That's even with a full factory reset.How are you installing them?
I fastboot load TWRP (without installing to the phone) then flash the .img to system partition. Good to go! I've never tried installing TWRP permanently, seems to work good loading it temporarily via fastboot.
Always seems best to start from stock Razer Oreo ROM before flashing GSI.
Peace
http://zackptg5.com/downloads/Disable_Dm-Verity_ForceEncrypt_11.26.2018.zip