EDIT: Keep in mind that this a rough layout of what to do, not a 100% solution for every case. This should be enough to get you started. Make sure you have a system for hiding/unhiding the text box. My implementation of this is similar to oldschool RPGs where you had to push A to progress the sequencer, allowing for the next bit of animation and dialog. Regardless of how you’re implementing it, it’s mostly the same kind of setup.
I had this problem, but found a solution. I made a custom empty blueprint actor, that you place in the level, that I call my cut scene text manager. It will take that text and update a text widget with the new text(not shown in pictures). Within the manager, you create a custom event(remember the name you give it) and give it an input of text or string or whatever you’re using, just remember the variable type. Name that input to something specific. This is critical for the next step.
Create a new struct file. Give it one variable of the same type you used in your blueprint and give it the exact same name. These have to line up for the sequencer stuff to work properly.
On the sequencer track, you include that actor from the level. Next, you add in a event track based on that blueprint.
Set your event trigger keys and edit the properties of them. The event name should match the event name in your blueprint. The parameter struct should match the struct you made. The text line should match what you want it to say. Copy/pasting of keys becomes your best friend.
Here are some screenshots of it working: