I’m experiencing this as well, but I believe there is a more specific issue with legacy Team Builder teams.
My team was originally created in CFB 25 and has been carried forward through CFB 26 and now CFB 27. In CFB 27 Dynasty, I can edit player gear, but I cannot edit Player Info, Ratings, or Style for the players on this particular Team Builder team.
What makes this especially clear is that I have created separate Team Builder teams in both CFB 26 and CFB 27, and those teams work normally in Dynasty — I can edit their players' information, ratings, and styles.
So this does NOT appear to be a general Team Builder editing restriction.
It appears to be something specific to Team Builder teams/players that originated in CFB 25 and were carried forward through multiple versions. The game is recognizing the players enough to allow gear editing, but their Player Info, Ratings, and Style fields are locked.
Please investigate the legacy Team Builder player data/conversion from CFB 25 → CFB 26 → CFB 27. There may be an incorrect editability flag, player ID, or legacy roster data being carried forward.
A conversion/refresh of the legacy Team Builder roster data would be much better than requiring users to completely recreate a team they have maintained since CFB 25.
A fix for this would without question help a lot of players that have created teams in CFB 25 that want to continue using those teams as the game improves year over year, me especially who plays dynasty more than any other mode on the game.