Remix OS 3 on surface pro 3


Had to replace my SP3 pro with a. Rand new version (i7 8gig ram and 256gig hd)
On the old one, I had no issues with duel booting remix OS and win 10 side by side, but for some reason I can’t do this with the new model! No boot option is coming up at all, can’t see grub.
Wondering if someone else got the same issues? Could it be win 10 anniversary update? (Rolled it back but still the same)