NextExecution set to midnight though job is scheduled for 8

Setup is 3 server only 2 of which service the default queue, the other is for more intensive jobs.

We have about 1500 recurring jobs for a subset of these jobs (around 190) the NextExecution time is always for the correct day but the time is set to midnight when as I said in the title most of these should be scheduled for 8am.

We use cron expressions to schedule the jobs for a lot of these jobs (the 190) the cron expression is 0 8 * * 1-5.

I have been digging around and can’t see any obvious reason these jobs are not scheduled correctly.