The thing people often forget about is that this kind of dream can also be your brain's way of saying "yo, you're checking your phone way too often". Not just general anxiety - it's literally your subconscious mimicking that pattern it sees on repeat. You try to read, it's blurry, it disappears... it's like your brain is reproducing that frustration of constantly being in "waiting for an important notification" mode without ever actually being able to process it.
Something that actually helps (and nobody ever mentions this), is putting your phone completely away from your bed at least 30 minutes before sleep. Not just on the nightstand - really in another room. Your brain "unplugs" from the notification/checking stress cycle more easily, and it changes your dreams like crazy. After a week or two, the pattern of blurry dreams starts to disappear.
The anxiety side that others mention is real too - it's not just a technical thing. But instead of torturing yourself mentally over "what am I missing", just try this little physical separation from your phone. A lot of the time when you stop the behavior for a few hours, the anxiety follows on its own. And bonus, you sleep better.