The material of Vision cages does not insulate extremely well, and the glass doors allow for heat escape.
Adding a heat pad in the center or on the cool end will help alot. Taping styrene foam on the outside back of the cage (and sides too if desired) helps alot as well. And if you need it, cover the outside bypass door with a slab of styrene foam.
Just because you set 95 on the temperature controller doesn't mean alot if the cage is large and the room is cool and the heater is small and on one side only. Kind of setting a thermostat to 68 deg when the outside temp is 40 degrees and your house is missing a wall. So try insulation first, then add more heaters as needed.
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Mark