GPSMAP 64st giving me fits!

First, let me say, I'm not new to GPS's. I have a Raymarine Dragonfly I use for boating and I just sold my Garmin Montana and purchased a GPSMap 64st for Geocaching. With that being said, I can not get the dang thing to route me to any Geocaches. I get the same error every time I try. "Route Calculation Error; maps do not have routable roads in this area".
Yes, the profile is set on geocaching. I have the following maps enabled; topo US 100k v5 and worldwide basemap. I also loaded a local area topo map. Any combination of disabling/enabling doesn't seem to make any difference. I tried setting up a custom profile and that made no difference. I have googled the issue and it seems common but every solution I've tried hasn't helped. i've even tried resetting to factory defaults and starting over. I looked on the geocaching site for answers and got no help there either. It's probably something small and I'm over thinking this--
Can someone help?

 

Thanks for the feedback- I actually found out that the "land-based maps" that Garmin uses are either something like an off-road/hiking/topo type OR the driving, navigating type. What I needed was something that has BOTH and both had to be "routable". Because most geocaches you drive to, then get out and walk the rest of the way and that could be a trail or in the woods or whatever. I did find one that has both. Called, US South Atlantic OSM-TOPO. I downloaded that map, put it on my Garmin and well-la! it worked! I picked the nearest cache and it had driving directions, then walking directions. Exactly what I was looking for.

 

Best support call I've ever had - and it was from Garmin. I'm not interested in driveable routes on the 64st but nevertheless had the same issue with "Route calculation error" with the Geocaching profile. I knew there was something called Direct Routing but couldn't find it for some reason. Quick walk through with Support: Main Menu, scroll to Routing, hit Enter, scroll up to Direct Routing (which for some reason I hadn't seen) and hit Enter. QED. I had thought Hiking as the activity on the Routing page would have got me what I wanted but no. Thanks for your followup, Snowlady, on the OSM-Topo, however.