Is delayed grief a thing?

Long story short, lost my hero, my dad in 2024 and took it in my stride because i was prepared for it, he was in the advanced stages of dementia.
However, I've found myself thinking about him much more during the past three months and finding it harder to look at photos etc, visit places that we used to love, basically the sense of loss is greater now than it was 18 months ago.
Am I experiencing some sort of delayed reaction?