If you see a next button, then you aren't using the automated process. You are using the manual process that is there if Javascript is disabled or for debugging. Also, the Next button is in the code at the very end of each step. It only appears when the process on the current page is complete. If there is more work to do, it appears if it thinks your server will time out when it tries to process more records.
This is all intended behavior.
For a specific process, it is possible we wrongly coded 'next step' instead of 'next batch' which would be a bug. But without knowing the step and by the description, it sounds like you are just reporting that the manual upgrade should be automated when in fact they are two different processes and you have "stepped into" the manual upgrader.
If you have a problem with the upgrader, you can reload and restart without manually applying a 'step' to the URL. Using 'step' will start the manual process. The automated process is aware of the last step (and even the last batch) that was completed. So clicking 'Continue' is safe enough. But if you have errors, sometimes it can be difficult to read the error message due to the small window size (the window cannot auto-resize itself once the process breaks with an error).