Greetings. I also post via Peakd, and for some time now—weeks, actually—I’ve been running into an issue where images won’t upload.
I’ve been getting around this by posting from my phone (since I don’t have a PC): I keep both Peakd and Hive.blog open, as if I were going to post on both. I draft the text in Peakd, upload the image via Hive.blog, copy the image code, and paste it into Peakd—and that’s it. It’s a bit of a hassle and takes some extra time, but it’s worth it. You might want to try doing it this way, too. I hope it works for you.