I had to migrate to the free OSRM router then, but its test server is down several times (it's not a production server) and it has only car navigation mode.
But, the UBPorts community is surprising me every time! Because from now, UBPorts will support the Mapzen cost (with itself money thanks to their donations) and you'll continue to enjoy uNav with the Mapzen navigation: car, foot, bike and even public transport mode, never down and so good routes.
I have not words to thank you the UBPorts! Its community, its interest, its so hard work, its vibrant motivation, its effort are being epic! Guys, you're incredible! Thanks!