The explanation of why this happens could become very long, it's related to how FSX and P3D3 and P3D4 handle Unicode text differently (they are all different), so this was an unfortunate side effect of trying to share code as much as possible without undeeded data duplication and update hassles.
It's only a cosmetic issue, since it won't affect the operations in any way so, all things considered, we gave priority to P3D having the better representation.
The other is issue is on my Flightbeam KSFO, recently purchased it does not show what terminal is what
The precise indication of terminals, with their proper real world names, it's only something available to airports with special GSX customization, which are only the FSDT ones. Any other airport will have terminal grouping exactly as in the AFCAD, as specified by the scenery developer.