It might have happened due to Cloudflare bot protection which is still on. People reported cases when build loading fails for some reason, after that I’ve tinkered a bit on CF side and it seemed to be fixed. IIrc it has something to do with changing stuff in the same GT tab for quite some time (e.g. an hour or so), opening a new tab fixed the issue back then. Not sure if this will be of any help.
AdBlock has nothing to do with it, you can turn it back on if you want.