Hello, Thanks for reaching out about the problem.
Seems it was a conflict with the new version of WP and Gutenberg
You should be good to use now without any issues.
Please check and let me know if you still have any issues.
Thank you!
I had this problem too,
and just solved that
open the primary file custom-search-plugin.php
find the function cstmsrch_init on line 61
then on the line 68 you should see
if ( ! $is_admin ) {
just replace that line with this code
if ( ! $is_admin && is_search() ) {
Hope that’s will help you to solve your problem too!
