Variations go missing now, if out of stock

After upgrading to 4.15.2 I find that any product which has variants selected by the “Text Label” option no longer display the text label at all, if out of stock. The product variant is completely missing. Before the variant was still displayed but marked out of stock.

This is causing customer confusion with emails asking if we have discontinued that option.

Is this something which can be corrected by changing a setting?

At first, try to reproduce the issue on the demo. It sounds strange

Thanks. The demo works properly. In fact it adds a X across out of stock variants. Also presents them in rounded-corner boxes instead of rectangular. Never seen either of those features even before we upgraded.
But I am pretty sure the missing-variant issue started with 4.15.2 and the demo is on 4.15.1
I do have “Show out of stock products” checked in Admin.