That will be something else. A10 is still supported, and it gets regular updates (last came just two weeks ago), see the changelog from Samsung: https://doc.samsungmobile.com/SM-A105FN/ROM/doc.html
If your phone is rooted, it might become ineligible for updates. You can try unrooting it. (E.g. using SuperSU app. If your phone isn't rooted, then this app won't work anyway, so no harm trying)
If that doesn't help, and you haven't done it already, a full factory reset maybe?