Meta Data missing on Export

I've got Lightroom Classic 11.5 and running Windows 10.

Just recently Lightroom has been missing out including the Metadata when I export files in jpg format. This means that when I go to sort images in date order it can't do that as it's missing the metadata. It's only recently just begun doing this over the past week - has there been an update that might be causing this?

I have to manually switch it on for Exports but then find it's unticked again, next time I open Lightroom up to process images. Any thoughts please?