googlebot always uses incomplte url and generates 301s

When googlebot indexes my pages it always uses a url without the trailing slash. This generates a 301 back to google which then looks for exact same page but with trailing slash added so it finds it with a 200 status code.

Anyone got any clues as to why google is always using the url without the trailing slash. I say always but maybe only most of the time.

I have the “Post Name” option selected in permalink settings so get the format of: https://www.mydomain.biz/sample-post/ for all my pages. (yes, all are pages, we don’t use posts) and its been like that for a couple of years.

So I don’t know what is generating the 301s as I don’t think htaccess in root is doing it (using default version) so it must be happening elsewhere.
But why is googlebot looking without the trailing slash ?

Thanks

p.s. everything gets indexed as it should and its not a major issue but is wastful of server resources and googles time.