Can't connect Galaxy S8 to Nikon D810 camera - worked fine on S6



I'm trying to connect my Samsung Galaxy S8 phone to my Nikon D810 camera to control it via the qDSLRDashboard app and the OTG adapter. The setup worked fine on my S6. Also, my two other Nikon camers (D610 and D750) work fine on the S8. So the only combo that doesn't work is D810+S8.

When I connect the D610 or D750 to the S8 I get a pop-up that asks which app I want to use. That doesn't happen with the D810 - it's never detected. Again, all three cameras worked with my S6 but only the D750 and D610 now work with the S8.

Can anyone think of how to fix this problem?