List of steps to reproduce (step by step, including full links if applicable):
*Problem 1: Try to block an IP address which is currently autoblocked (e.g. to extend the block length).
*Problem 2: Try to block an autoblocked IP where the account responsible has also been globally locked and hidden
*Problem 1: After the new block has been submitted (but not before), the block form says that the "[IP address] is already blocked", with no option to re-block. The new block is not successful. Appending /32 for an IPv4 address does make it work.
*Problem 2: The same, but the only error message is "The user you are trying to block has already been blocked and hidden. Since you do not have the hideuser right, you cannot see or edit the user's block" - this is for the IP address.
What should have happened instead?:
Previous behaviour would be to not display any error for an autoblocked IP, which I believe is the correct behaviour, however an option to re-block should at least be provided.
Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc:
This is on English Wikipedia 1.37.0-wmf.16 (cbd846f), and it seems to have been introduced very recently