Invalid date being reported in Foreman UI

invalid date for content hosts and sync status/plans
Expected outcome:
date to be shown
Foreman and Proxy versions:
3.6 / 4.8

New setup of Foreman 3.6 with Katello 3.8 on EL8
OS is set to UTC
Settings in Foreman are UTC for new users (cant see anything for current time though admin or another user)

Have set a sync plan for daily but next sync date shows invalid date.
2 test content hosts have been subscribed successfully but both show ‘registered’ and ‘last checkin’ as invalid date.

Any advice on how to fix this? Can only see one post for this online from rhat and suggests running a foreman-rake reimport command

Is this on Firefox? I remember seeing some issue around this that I can’t remember if it was fixed.

yes it is, but I will check with chrome. Our previous setup didnt have this issue using firefox, will also try a restart of all foreman services and see if that fixes it

ha, so yeah it’s a firefox issue! Chrome displays everything OK
Will try cleaing cache but and will run ffox dev tests to finds out whats causing it

Did you set a time zone in your Foreman profile?

yes, it’s set to UTC

OK. I thought an undefined setting could be a cause for this problem. Or was it an undefined locale? If you also have explicitly defined the language, then I don’t know what else could cause it.

I think it’s some JS incompatibility issue with Firefox. Is upgrading Firefox possible? Or check the firefox version and we can try fixing the incompatibility.