plain_text_input default_value is not populating on iOS

You can see from the screenshots below I am viewing the same exact message. Light mode is on iOS mobile, and dark mode is on desktop.

The comment on mobile shows up as empty. Even if I click on it, the text does not show. The odd thing is the data is still there, because if I hit submit, it sends the data through still and works as if the comment was there.

(Filling out the following with as much detail as you can provide will help us solve your issue sooner.)

@slack/bolt version: "@slack/bolt": "^4.2.0",

Your App and Receiver Configuration

export const slackApp = new App({
token: process.env.SLACK_BOT_TOKEN,
signingSecret: process.env.SLACK_SIGNING_SECRET,
socketMode: true,
appToken: process.env.SLACK_APP_TOKEN,
});

Node.js runtime version

v23.5.0

Steps to reproduce:

• Send a message (in thread), setting the initial_value of a plain_text_input. Check it on desktop, then check the same message on mobile.

Start by reproducing the issue with a threaded message containing a plain_text_input whose initial_value is set, comparing Slack desktop and iOS behavior. Trace how Bolt represents or sends the input configuration and determine whether the discrepancy is within bolt-js or Slack's mobile client. Done means the initial text is visible and editable on iOS without breaking submission.