WordPress returns empty page

the site seems to be infected by malware:

https://sitecheck.sucuri.net/results/https/webscraping.pro

which could explain the issues you have; these guides should help you deal with malware removal:

https://wordpress.org/support/article/faq-my-site-was-hacked/

https://sucuri.net/guides/how-to-clean-hacked-wordpress/