So, I've just now myself experienced this issue, and I have a hunch now that it might have something to do with elements being injected into header/footer. For context, I had no Custom CSS employed on our site, however we do have one of those floating BBB badge elements injected in the footer and a GTAG in the header. I today tried injecting what I later realized was malformed code into the footer after the BBB badge. After reverting to how it was prior, I started experiencing the jump to home when adding a block bug. Dumped Chrome session, dumped cache and cookies, tried firefox. Nothing worked. What I ended up doing was deleting ALL injected code in our header and footer, saving, then re-adding it all back in. Fixed.