Hitting send unexpectedly triggers predictive text completion

[Jaffex]

Steps to reproduce

With predictive text turned on in iOS 17+ (Settings > General > Keyboard > Predictive Text), try writing some text that gets predicted (indicated by a grey suggestion inside the message composer)

Outcome

What did you expect?

I would expect similar behavior to iMessage and other messaging apps.
Coming to mind are:

1. Sending a message while having begun to type a word that gets predicted, it gets completed when hitting send (This is working already)
2. A word you didn't even begin to type, but got predicted, should not be completed upon sending
3. When hitting backspace, predicted text should not be completed

What happened instead?

1. Worked as expected

2. The word "time" in the below screen capture was predicted, but the user did not show intent to actually want it in the message. iMessage would only complete the word if you at least had entered a "t"

RPReplay_Final1698771975.mp4

3. Seen below is the most confusing interaction: When a text is predicted, but the user changes their mind and hits backspace to correct their already written text, the predicted text gets completed in the composer and gets mixed up with whatever remained after the user's correction

RPReplay_Final1698772170.mp4

Another example:

RPReplay_Final1698852721.mp4

Your phone model

iPhone 12 mini

Operating system version

iOS 17.1

Application version

1.4.0

Homeserver

Synapse

Will you send logs?

No

[Jaffex]

The issue was renamed to imply that only hitting send would trigger unexpected completion behavior - in light of this I just wanted to chime in once more to point to the 3rd point of the report:

Seen below is the most confusing interaction: When a text is predicted, but the user changes their mind and hits backspace to correct their already written text, the predicted text gets completed in the composer and gets mixed up with whatever remained after the user's correction

Where hitting backspace also triggers completion.