One other vendor of WiFi4 and WiFi5 router, which use open wrt 19.07.x firmware and support mixed mode forWPA2/3 Personal, reporting its need by some clients to reconnect once (setup the connection to the client new by typing the password). I have the same experience with WiFi5 router which supporting mixed WPA2/3 to WiFi6 client devices. No problems, after first new logon by typing wifi password.