Whatsapp Blue Ticks And Read Receipts

[shivvy]

I understand that the 3 stages of whatsapp delivery are:
1 grey tick = sent
2 grey ticks = received
2 blue ticks = read and comes along with a time stamp
I need help understanding the following situation. . .
In a group chat conversation one members ticks go to two grey ticks but over the course of a week don't turn blue. Then one day all the ticks on multiple messages turn blue and they all have different date and times on them,
Does this mean that the person had disabled the 'read receipt' function (and that's why the ticks didn't turn blue), but then when they turned the read receipts back on again the date and time that they read the messages shows up?
Is this right? Or is there another reason why this situation might occur?
Thanks

[shivvy]

I hope this makes sense to someone!