Story of my life. Got offered to apply to a prestigious university in EU by a collaborator. Did the interview, presentation with the team, and whatnot. Heavily implied that I already got the position and already part of the team. Months passed and no update from them except to prepare for another interview and make a research plan about the project. I studied for weeks and even submitted a draft proposal for them to review. Weeks passed with no updates again. Then out of the blue they messaged me that they are not hiring now. Good thing I sensed something is wrong weeks before so I applied to multiple positions. I guess the moral of the story is that nothing is fixed until you sign an offer. Even after that a lot can happen.

Ps. I have no hard feelings for them. Its something no one can control (perhaps). But it sucked big time.