There is no consistency to when the errors happen, and within about a minute or two a refresh of the page “fixes” the issue. But then of course, it will happen again with time. Deleting the
.htaccess file causes a 404 error and will not regenerate the file. I know that this is usually caused by bad plugins/themes, however the issue doesn’t last long enough/is consistent enough to be able to test by disabling individual plugins.
Read more here: Constant 500 Internal Server Errors on WordPress Site