I and everyone I have checked with are unable to rename a stack of items in an anvil as of 1.11.1 and higher, I have verified that it was possible in 1.11 and before, attempting to name a stack of blocks makes it appear that you will only receive a single named block, but attempting to take said block results in the anvil gui being reset to before the naming. naming of single works fine
Environment
Windows 10
Duplicate of MC-111699. Please go and upvote that ticket instead. Also please use the search function next time before creating a ticket to save everyone a lot of time.