I activated the Read More button after buying the pro theme.
While it works on blog & archives, it doesn’t take people to the article when clicking “read more” on the blog posts listed via the Latest Posts block on my homepage.
The Latest Posts Block is part of WordPress core. There is a bug in their code. It will will be fixed in version 8 of the Block Editor which will be part of the next major update to WordPress 5.
The theme and GP Premium has no way of changing this. You will find the same bug if you switch to other themes.
The alternative to using a better plugin is to install the official Gutenberg Plugin which will bring the editor up to version 8.
If it helps, this is definitely a WP issue not a GP one as I have had exactly the same problem and seen it on other sites using the block. I resolved this by using the GeneratePress WP Show Posts plugin which also gave me more options for the display.