Yes, there have been stories about domain front-running for years. You want to use whois from the command line instead of Web sites to look up domains.
Another idea for folks who are either less paranoid or doing lower stakes hobby projects -- I often search for the domain I want but without the TLD. If I wanted "foobar.rocks" I search for "foobar" on my registrar (Hover) and they run a search for "foobar" on all TLDs they support and I can tell if the one I want is available or not. Not 100% fool-proof against front running but it's good enough when I search/buy domains for my low stakes projects.