unable to connect riseup.net with Bitmask VPN active
I apologize in advance for the probable simplicity involved in dealing with this issue, but any help will be sincerely appreciated. I've also searched archived messages here and elsewhere on the internet before asking this question.
In brief, I am unable to connect riseup.net email or the internet with Bitmask VPN active. I'm using OS 10.12.6 and Firefox 57.0.1 and using Thunderbird to access my riseup.net email address. The Bitmask account is new, but the riseup.net email address is a couple of years old.
Per instructions from riseup, I created a new address to use Bitmask Black. Bitmask seems to connect as the dialogue box shows the VPN is active. Once I've connected, neither Firefox nor Thunderbird can access the internet. For that matter, neither can the Tor Browser bundle. I've contacted riseup and I was referred here.
I'm sure there's a configuration problem, but I don't know what it is. I'm using Google's DNS. I don't know if it's an IPv4 or IPv6 issue, but here are test results for that: Test with IPv4 DNS record ok (0.280s) using ipv4 Test with IPv6 DNS record bad (0.153s) Test with Dual Stack DNS record ok (0.216s) using ipv4 Test for Dual Stack DNS and large packet ok (0.127s) using ipv4 Test IPv4 without DNS ok (0.455s) using ipv4 Test IPv6 without DNS bad (0.254s) Test IPv6 large packet bad (1.591s) Test if your ISP's DNS server uses IPv6 ok (0.393s) using ipv4 Find IPv4 Service Provider ok (0.389s) using ipv4 ASN 209 Find IPv6 Service Provider bad (0.175s)