Your friend saying “it’s whatever” three times in one day isn’t whatever.

People rarely announce that something hurt. They dismiss it, and then they dismiss it again, which is how you can tell it keeps coming back up for them. The repetition is the signal rather than the words themselves. If it really were nothing, it would not need saying three times in one day.

Count, gently, and if you hear the same brush-off more than twice, ask once: that is the third time you have mentioned it, do you want to talk about it. If they say no, let it go and stay nearby. The offer still matters when it gets declined.