RSS-Formatting stopped

Hi!

Today I noticed a strange problem with my RSS feed.
(https://www.spitblog.de/feed/)

From one day to another the german umlauts disappeared, the same happened to the photos and formatting attributes, like bold or italic parts.

So I installed the “o42-clean-umlauts”-plugin (https://otaku42.de/2005/06/30/plugin-o42-clean-umlauts/) to get at least the umlauts visible again.

But where did the formatting go?

Regards,
Lars