Author function removes read more

I tried adding both functions (read more and author) following instructions here:
http://www.billerickson.net/code/display-posts-shortcode-show-author/
and here:
http://www.billerickson.net/code/add-read-more-to-display-posts-shortcode/

They work if included individually in the functions.php, but they don’t work together. If I add author function the read more link dissapeares. I assume it’s because the output is reconstructed in the function.

How can I make them work together?
Many thanks.

https://ww.wp.xz.cn/plugins/display-posts-shortcode/