Visits over time stopped working

Hi, I’m a bit of a novice using analytics. I have Matomo set up on my server for a few sites. It has worked fine up till now, but a client pointed out this anomaly to me, so here I am, asking for some advice!
Basically the “Real Time Visits” is working, showing 107 visits in the last 24 hours. However, the “Visits over time” box is showing that there have no visitors for the last 3 days - which isn’t right. (I’ve been monitoring it since yesterday) This is obviously what my client looks at (and shows to her bosses!) I was wondering if this was a common occurrence? Is it likely to sort itself out? Is there something I can do!! All the other sites I’ve got seem to be working fine. I guess that this is the only site that is not hosted on my server, it is on the company’s own hosting package - not sure if that would make a difference - if something changed on that server could it cause this?
I’ve attached an image of the dashboard.
Thanks in advance!

Hi,

If you see all visits fine, but all reports aren’t updating, then archiving isn’t running properly.
Do you have set up cron? If so, can you make sure it is running successfully?

Hi, There is no cron job set up, just the default Matomo installation.
However - I just checked it, and it seems to be working again. It didn’t record anything on Tuesday or Wednesday, but since then it has recorded visits. So it was maybe just a temporary glitch.
Cheers,