FWIW, I newly have this problem (powershell in constrainedLanguage), which suddenly started in late January 2025. Not sure if it's related to a windows update or what. Machine is hybrid-joined win11 23H2. I cannot find any group policy, intune config, or defender policy which restricts what can run. I also cannot run .bat or .cmd files (SAYS "This program blocked by group policy"), so it's ACTING like there is some sort of restriction set, but I cannot find one on the domain or in intune. Have not tried random rolling back patches yet.