After I converted my WordPress install to 100% SSL I noticed that my own feeds in Tiny Tiny RSS were not updating. Years ago I forwarded my RSS feeds to Feedburner and 301 redirects from https://blog.dembowski.net/feed/ https wasn’t working.
I can’t even remember why I used Feedburner. I’m pretty sure I turned it on in a moment of “What’s that button do? *Monkey pushes button*”.
I’ll keep testing but eventually I’ll disengage Feedburner and just use https://blog.dembowski.net/feed/ instead.
Edit: This work around seems to fix it.
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{HTTP_HOST} blog.dembowski.net [NC]
RewriteCond %{SERVER_PORT} 80
RewriteCond %{REQUEST_URI} !^/feed/$
RewriteCond %{REQUEST_URI} !^/index.php$
RewriteCond %{QUERY_STRING} !^feed=rss2$
RewriteRule ^(.*)$ https://blog.dembowski.net/$1 [R=301,L]
</IfModule>
The part starting at line 5 is where I added conditions so that the SSL 301 redirect will be ignored.