There's a "Bools as Char" option in psqlodbc. Try turning it off. If you're using DSN, the option is in page 1 of the Options dialog box. If you're using a connection string, add "BoolsAsChar=0;" to it. See https://odbc.postgresql.org/docs/config.html
Disclaimer: I've never used this option myself so can't say for sure. I actually use smallint instead of boolean in my design.