Cannot enable Active mode

whatismyip.com displays both my public ipv4 and ipv6 addresses.
With only ipv4 enabled the log shows:
Connectivity (IPv4): Determining the best connectivity settings...
Connectivity (IPv4): Local network with possible NAT detected, trying to map the ports...
Connectivity (IPv4): Port mapping: Successfully created port mappings (Transfers: 12345, Encrypted transfers: 23456, Search: 34567) on the "XYZ" device with the MiniUPnP interface
!myinfo on a hub shows "Mode: A", but search doesn't work and downloading filelists always times out, so it looks like I'm in Passive mode after all.
With only ipv6 enabled the log shows:
Connectivity (IPv6): Determining the best connectivity settings...
Connectivity (IPv6): Public IP address detected, selecting active mode with direct connection
However now !myinfo on the same hub shows "Mode: P" and of course I'm still in Passive mode.
So my question is - why can't I seem to actually enable Active mode no matter what, despite the client even stating that I am in Active mode when only ipv6 is active?
With only ipv4 enabled the log shows:
Connectivity (IPv4): Determining the best connectivity settings...
Connectivity (IPv4): Local network with possible NAT detected, trying to map the ports...
Connectivity (IPv4): Port mapping: Successfully created port mappings (Transfers: 12345, Encrypted transfers: 23456, Search: 34567) on the "XYZ" device with the MiniUPnP interface
!myinfo on a hub shows "Mode: A", but search doesn't work and downloading filelists always times out, so it looks like I'm in Passive mode after all.
With only ipv6 enabled the log shows:
Connectivity (IPv6): Determining the best connectivity settings...
Connectivity (IPv6): Public IP address detected, selecting active mode with direct connection
However now !myinfo on the same hub shows "Mode: P" and of course I'm still in Passive mode.
So my question is - why can't I seem to actually enable Active mode no matter what, despite the client even stating that I am in Active mode when only ipv6 is active?