If your person has been moved from a Texas state or federal facility to a correctional facility at a military installation, the most likely explanation is that they are active duty military or have a military background that makes them subject to the Uniform Code of Military Justice in addition to, or instead of, the civilian criminal system.
Fort Bragg in North Carolina and Joint Base Lewis-McChord in Washington state are on opposite ends of the country, so knowing which one applies matters for understanding the situation. Both installations have military correctional facilities that house service members who have been convicted through the military justice system, court-martialed, or who have pending military disciplinary proceedings running alongside or separate from any civilian charges.
The United States Disciplinary Barracks at Fort Leavenworth in Kansas is the primary long-term military prison for Army personnel, but regional military installations also have confinement facilities for shorter-term or pretrial military detainees. If your person is Army, a transfer to a facility at either of those installations suggests military justice proceedings are involved.
This is a significantly different legal system than civilian corrections. The Uniform Code of Military Justice, the Manual for Courts-Martial, and the military appellate system all operate independently from civilian courts. If your person is facing military justice proceedings, they need a military defense attorney, specifically a Judge Advocate with court-martial experience, rather than a civilian criminal defense lawyer.
Getting clarity on exactly which facility they are at and what branch of service is involved is the essential first step in understanding what comes next.