Speak Screen automatically shuts off

I have recently been using the accessibility feature on iPhone “Speak Screen.” At first it worked well but lately the app will read me a few sentences (or just half of a sentence) and shut off. I don’t understand what’s causing it to automatically shut down when I haven’t asked it to. It’s also confusing because before, the feature was working as expected.

For more context: I use the “Speak Screen” feature read things I’ve written in Google Docs. Hearing it spoken aloud helps me catch and fix any errors. The first week of using this feature worked very well. However, it suddenly began shutting off on me and I can’t figure out why.

Under the “show controller” screen, I have the setting on: “long press - read all content.”