Oh I see. You definitely should be able to delete sections and then you can decide what you want to do with the tasks inside this section:
Now in regards to also moving the last section left I remembered we discussed this here.
Can you check if you have a filter or sort enabled? Sometimes when you have something selected under sort it won’t work. So double-check to ensure “sort” is set to none and no filter.
Let me know if the buttons to delete the section are still greyed out then.