Entire website breaks for a few minutes after opening plugin page

I have recently installed the Sucuri plugin on a website. At first, the website loads as normal without any issues, but as soon as I go into the Sucuri dashboard it says “Loading…” in two places on the page for at least a few minutes, and while this is happening it breaks the both the public and admin areas of the website for that entire time (it leads to a 500 Request Timeout error).

Once the dashboard loads or times out it eventually allows the rest of the website to load correctly, but every time I go back to the Sucuri dashboard the process repeats and the website breaks again, meaning I just can’t use this plugin.

Is there a fix for this issue?

Thanks