@troed I see!
I had a quick look at the code and I assume that FediFetcher has issues with the API (inbox, outbox, followers, ...) beeing on a different domain then the blog (public-api.wordpress.com and blog.troed.se). The NodeInfo and WebFinger endpoint are (and has to be) on blog.troed.se (https://blog.troed.se/.well-known/nodeinfo) but all other endpoints are on public-api.wordpress.com.