I finally bought an offset seatpost that had the most offset I could find. ( 31mm?)
This did this for both of my bikes that have Brooks saddles.
I believe the railing attachment on brooks saddles is somewhat too short.
I've experienced similar problems as the OP but finally realized my feet needed to be further forward, at least this is what it felt like, which turned out to be correct. Hence the offset seatpost.
Last edited by boomhauer; 10-03-18 at 10:42 PM.