Slack mobile shows "Unable to show preview" despite fallback text() being present

[daniel-b2c2]

I have specified fallback text via the .text() method, yet the text displayed in the Activity section for my bot's post shows 'Unable to show preview. Tap to see the original message' I would expect this for rich text with a missing fallback, but not when the fallback is specified.

Reproducible in: None

mvn dependency:tree | grep com.slack.api
gradle dependencies | grep com.slack.api
java -version
sw_vers && uname -v # or `ver`

The Slack SDK version

(Paste the output of mvn dependency:tree | grep com.slack.api or gradle dependencies | grep com.slack.api) 1.38.1

Java Runtime version

(Paste the output of java -version)

openjdk version "11.0.20.1" 2023-08-24 OpenJDK Runtime Environment Homebrew (build 11.0.20.1+0) OpenJDK 64-Bit Server VM Homebrew (build 11.0.20.1+0, mixed mode)

OS info

(Paste the output of sw_vers && uname -v on macOS/Linux or ver on Windows OS) ProductName: macOS ProductVersion: 14.3 BuildVersion: 23D56

Steps to reproduce:

(Share the commands to run, source code, and project settings (e.g., pom.xml/build.gradle))

var blocks = ...; //blocks is some complex rich text arrangement. doesn't really matter what the arrangement is.
return ChatPostMessageRequest.builder().text("Ancient Version Report: 2 items reported.").blocks(blocks).build();

Expected result:

As a slack mobile user, on the Activity panel, selecting All (where the above text results in a keyword notification for me) to show the fallback text "Ancient Version Report: 2 items reported'"

Actual result:

On the slack mobile app, on the Activity panel, an entry is displayed, but the text is summarised as "Unable to show preview. Tap to see the original message". I would expect this to happen if I had not provided the fallback text, but the .text() method suggests that I have.

Requirements

Please make sure if this topic is specific to this SDK. For general questions/issues about Slack API platform or its server-side, could you submit questions at https://my.slack.com/help/requests/new instead. :bow:

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