Colour not taken to roots - even after bleaching…

I only do my roots every 3 months or so, so as normal, yesterday evening, I bleached my roots, rinsed, dried as I normally would and went to bed.

This morning I applied colour (La Richie, Midnight Blue), as I normally would and I used the rest of the pot to patch up any bits that needed doing. I sat with it on for an hour and rinsed and dried as normal (I know the instructions say leave for 15mins, but I’ve never had an issue with leaving it longer in the past)

However, the colour has barely covered my bleached roots. I didn’t have time to fuss, so I styled it, went to work and whatever.

I came home and thought I’d do my roots again using a different pot of colour, same process, let it sit for an hour, rinsed and dried. Again, the roots are very patchy and you can still see the bleached colour underneath.. does anyone have any advice? What could have gone wrong.

I’ve used this brand before and never had any issues, the other bits of hair I patched up took the colour fine, so it’s just the bleached roots that haven’t taken which is a bit strange.

All advice appreciated.