I don’t understand how that is allowed.
Does he still have free speech?
Freedom of association?
Can they quarter soldiers in his house now?
Illegally search him?
Slow trial?
Cruel punishments?
etc...
Basically yes. Once you’re convicted a judge can limit your fundamental rights as terms of probation (i.e., if you don’t agree you stay in jail). A judge can order you to stay away from specific people, submit to random searches, and so on.
State law can remove rights from felons, such as the right to vote.