I am a user of Slack on iOS with VoiceOver. I sent the following message about a recent accessibility regression to the Blind-Slackers discussion group, which I also own and moderate. Those who wish to subscribe can send an email to
Blind-slackers+subscribe@groups.io
It is currently a low traffic list.

From: blind-slackers@groups.io <blind-slackers@groups.io> On Behalf Of David Goldfield via groups.io

I don’t know if others have noticed the following issue.
On many screens in Slack for iOS, performing the two-finger scrub gesture does move back to the previous screen as it should.
However, iOS no longer plays the familiar earcon that you hear when moving to another screen or page. This could give you the impression that the command was not performed.
I have reported this bug to Slack and I am pleased to say that they have been able to duplicate the bug and are bringing this to the attention to their accessibility team.
This is a recent regression as this used to behave normally.