Do you have this problem when a default theme is activated on your site?
Have you tried to disable plugins? Maybe some of 3rd-party plugins conflicts.
Turn on debug mode in WordPress – https://wordpress.org/support/article/debugging-in-wordpress/ to find out what error appears on your site, it will point you in the right direction what needs to be fixed. Contact your hosting provider to check the situation from the server-side, check the server error log.
As I can see, after testing the site via gtmetrix, you need to optimize images, for example – https://prnt.sc/u0cp7b and change settings of banners on the home page – https://prnt.sc/u0cpei – https://prnt.sc/u0cpu5
