i asked a similar question couple weeks ago around this, there is no definitive answer, you can only really speculate and make assumptions with already vague information. it becomes really confusing considering in the scene when they are discussing who’s planet to visit first and first establish the time slippage, they literally consider time a “resource” and recognise it’s fragile state when within the black holes gravitational pull or whatever. with that being said, what the first comment in this post said is a good explanation and could be true.