After you create a new process, you will be navigated to the process editor screen. Once there, if you click the (+) to create a new task there is an option to create either a "Rule" or a "Step". After you select "Rule" you can enter in the rule name and bool details in the pane on the right.
It looks like step 2 has "end process" as the next step in progression. Can you check if removing that restriction will allow you to enter a new task in the process? It looks like in the original screenshot you had the ability to add tasks as two were listed - can you try to create a new process and let me know what your options are then?
Also are there any nuances to your access in the target model? Wanted to confirm there are no permission related issues there as well.