Hello, Shehzad Ghazi
The mentioned situation is not a bug.
The stock status is generally displayed together with the add to cart form ( they are in the same file) on single product page. Therefore, when the catalog mode is enabled, the add to cart form is blocked and the stock status can not be displayed (even if it is a simple stock status displaying – https://prnt.sc/KrPLztTIsA4m ).
If you want to change the current situation, then the desired result requests additional customization in files, that are outside the scope of our basic support, sorry.
Best Regards,
8Themes Team