Don't want to be picky, but performance 1 slot 1 is PC#0, performance 1 slot2 PC#1 and performance 2 slot 1 is PC#5. You missed the counting from zero I guess.
The PROFILER refers to the logical range of 1-128 across the board. This applies to program changes in Browse Mode as well as Performance Mode. It also applies to MIDI banks. Consequently, while no Remote is connected Performance 1 Slot 1 displays program 1 and bank 1 in the dark box on the left.
The numeric range is 0-127. Some devices refer to that. That's why you sometimes have to deal with a gap of 1 in the world of MIDI.
Program changes are sufficient in Performance Mode as long as you stay within the same MIDI bank e.g. from Performance 1 Slot 1 to Performance 26 Slot 3. If that's sufficient, you don't need MIDI bank select. At that Slot the 128 program changes are exhausted. A bank starts with Slot 4. To load that you need to send bank select LSB 2 (numeric 1).