Gotcha upgrading 3.2.0 to 3.2.1

Been running 3.2.0 OK on MAMP PRO 6.6.2 upgraded to 3.2.1 as per the instructions and the base URL defaults to /maintenance with “Site under maintenance” page displayed

Open URL directly to /admin and it prompts to update Database, do so and then redirects to the Admin login and things are hunky dory. Weird behaviour