We suspect on why these might happen and we avoided them by clearing pre gunship circular spire completely. I don't know if that was just a luck streak, but whenever we cleared whole spire pre-gsb, we've never had issues with dbs teleporters/door not spawning and could continue Icc normally.
Thanks for your advice, but everything and every way we do our tactics are already reviewed and heavily thought in order to get the best outcome possible. There are reasons behind most things we do. I can assure you that after clearing out some mechanics and how they work in molten, we only wiped once, and that was cause of me. Green was never an issue this way and was effectively dpsed down.
EDIT: Thank you both for posting here, we didn't have people outside the guild giving us feedback on this very forum post for more than a while.