macOS/Linux - DNS Failing when connected to a VPN

Hi,

I've been struggling with this for a while and was wondering if anyone here had already solved this issue before. When I connect to my VPN (I am using ExpressVPN specifically) and try to run Amass with active enumeration, I get back the 'No DNS resolvers passed the sanity check' error. At first I thought this was an issue with my system/DNS configuration and not Amass itself - but I noticed that DNS lookups via the command line, in browsers, all worked fine, and I also wrote a quick script with dnspython and confirmed that that all seems to be working too - so now I'm wondering if this is an issue with Amass, or perhaps something to do with golang in general?

I also tried the same thing on Linux - same VPN and all, and I get back the same error. On Linux I've tried adding Google's NS to the etc/resolv.conf file, and still no luck - similarly in Mac I added 8.8.8.8 to my DNS servers in System Preferences with no luck. I'm going to try installing by building from source and see if that changes anything, but I'm not hopeful.

The reason I'd really like to get this working is that I seem to get rate limited by either the DNS servers or my ISP pretty quickly whenever I try to use brute force mode, even when I lower the max concurrent DNS queries setting. Has anyone seen this before, or have any insight into why this might be happening?

Thanks in advance!