On my 2015 195RB there is no fan speed control on the the thermostat - only an ON/OFF and Temperature. The top one is the ON/OFF and the bottom one is the temperature. The behavior of your top switch is exactly like mine - very hard to move and only two positions. With the switch over to the right it's OFF and to the left it's ON - and requires some effort. Also, on the top switch on mine it has "OFF" printed on the switch with an arrow pointing to the right. However, you almost can't read it without a magnifying glass. It sure sounds like you have the same thermostat as mine.
TT: 2015 Jay Flight SLX 195RB Baja Edition
TV: 2014 RAM 1500 Bighorn CC, 5.7L Hemi, 3.21, Factory Air Suspension/Tow Pkg, Andersen WD/SC