At the time of writing, my experience as a parent is limited to 10y. Combine this with my extensive experience as an offspring, which spans to the present day as my parents are still in this world, I can report one thing with confidence: Whenever you feel a distance growing between you and your kids, it is your responsibility as a parent to bridge it. The longer you wait the longer the distance will grow. Sometimes, parents feel that by standing their ground, kids will understand where they’ve gone wrong.
This approach is not fruitful, a distant parent can’t and won’t pass any messages to the child; it will push them away into an introvert defense. Even if there was a point in the first place, it will end up vanishing altogether as the child will grow defensive. Moreover, as time passes in distance, the only point a child will get is that of indifference.
It might feel beyond your power, or a spoiling move but when you begin to doubt whether you should continue in distance or reach out for one more time, then you need to swallow your pride and reach out. Even If nothing happens and the gap does not bridge you will at least feel some closure knowing you have done everything you could.