All of my domains have DNS on Dynadot except one that has DNS on Cloudflare. While in browser they all resolve, in the real time testing tools from Google, such as here, https://search.google.com/test/mobile-friendly/result?id=bcR13UYx5hhBlvp4vuhY5A, all Dynadot DNS domains give crawl error. The detail of the error is that it failed to reach the DNS server. (Dynadot chat support is denying any issue.)