Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I just got an STX a few days ago and I have to say I'm rather underwhelmed (coming from Realtek ALC892). Like you, I find that the bass is lacking and it is very bright and the treble is somewhat harsh.
What OP amps did you change to?