FT8 Transmitted Signal in Panadapter

Your spectrum is probably fine.  The one above is.  Notice the symmetry of it which is indicative of a properly generated signal.

You have to ignore the signals assumed to be spurious emissions.  When we show the transmitted spectrum, we use the receiver in the radio to show the actual transmitted RF coming from the DAC and that will have harmonic components of the primary signal.  Also, some of these "signals" are harmonics from the DSP in WSJT-X when it generates the FT8 (or whatever mode you are running) tones.  What is actually transmitted as RF are only the signals inside the TX filter.  And also pay attention to the magnitude of the signals too, most of them are -125 dB down and almost 90 dBc, more than twice the FCC requirement for spurious emissions (but that is moot since they are not being transmitted as RF).