No. Good time credit is applied equally to all federal inmates regardless of the offense they were convicted of. Every inmate receives the same 15% good time credit from the day they are incarcerated. What happens to that credit after that is entirely up to the inmate.
The only way good time gets reduced or eliminated is through the inmate's own behavior. Incident reports, disciplinary infractions, and rule violations are what put good time at risk. An inmate who follows the rules, stays out of trouble, and keeps a clean record holds onto that credit regardless of what they are in for. An inmate who accumulates violations loses it regardless of what they are in for.
The perception that sex offenders are treated differently in terms of sentence calculation is understandable given how much additional punishment follows them after release. Registration requirements, residency restrictions, supervision conditions, and public record databases mean the consequences of a sex offense conviction extend well beyond the prison sentence itself. That reality is significant and it is lifelong for many people in that category.
But inside the walls, the good time calculation does not distinguish by offense type. The math is the same for everyone on day one, and conduct from that point forward is what determines whether it stays intact.