leeks all gone seed

Hello and welcome to the forum.
I don't know where you are (could you put your location in your profile please ) so this comment may be absurd if your climate is very different to mine.............. but has your soil dried out like it has here.

They will bolt if they've been stressed, which is usually because they are dry at the roots.

Some of mine have bolted this year, a problem I've never had before.