I'm responding here with the resolution from our email conversation, to make sure if any future users encounter a similar issue as you did, they're aware of what things they need to check.
For future visitors to this thread, remember that there's going to be two ways to clear out text blocks - either deleting the entire row/section they're in, or deleting them individually by clicking the trash can in the formatting toolbar.
The option for deleting a row/section will display in the very top-right when you're hovering your mouse over it. That means if your section includes a very long singular column (i.e. with a newspaper / newsletter design), then you may need to scroll up to see that section's editing options for deleting, copying, or filling with a different color.
For individual text blocks, when you click into them, the formatting toolbar will automatically display at the top of the editing screen. However, the toolbar has a lot of options in it, meaning that some options may inadvertently get cut off (like the trashcan icon at the very end of the right side), depending on how zoomed in you are on your browser screen. When I've seen this occur, it's at a very specific zoom level, and is easily resolved by zooming in one step (causing the toolbar to change to its 3 dots menu condensed version), or zooming out one step, so everything displays at the smaller scale. You're welcome to adjust the zoom of your screen as you like, based on your personal preferences, needs, and screen size / resolution settings.
For a visual example of what I'm referring to, see the below images:
100% view:
125% view:
150% view:
If you'd like additional visual and step-by-step guidance on managing your action blocks, as well as editing sections in general, I'd recommend these two articles:
Add, arrange, or delete blocks, layouts, and sections in your email template
Add, move, and customize sections within your email template
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