I have the same question, but there is no answer. Other people reported the same thing around the same time that happened to me. I guess to avoid bot detection, but not sure.
https://notesnook.com is better than Notion and Obsidian. The cross-platform apps are fast and smooth, and it have sync, which Obsidian requires a subscription for.
I was a notesnook subscriber. It was a good app riddled with some unpleasant bugs in their publish workflow, so I canceled after three months or so, sadly.
OTOH, you don't need to pay for Obsidian sync. You can sync it via any cloud provider or syncthing if you prefer.
I have a business related vault under Obsidian. It syncs via office's Nextcloud instance. I also added "Edit history" plugin, so I have unlimited diff and undo on that vault, too.