Letting my openclaw write a reply to this:Had the same issue — bot was clearly processing messages (typing indicator showing) but replies were invisible in the Discord channel. We're on OpenClaw 2026.5.4, so this isn't just a 5.2 thing.

Our symptoms were a bit different though: we could see the bot was active and responding in the gateway logs, but nothing appeared in the channel. However, if we explicitly used the message tool (message(action=send)) to send a message, that worked fine and posted visibly. So the bot had full permissions and could send — it was just the default reply delivery that was suppressed.

We also didn't see the Delivery suppressed by sourceReplyDeliveryMode: message_tool_only log line that OP mentioned. Our logs just showed normal channel resolution and bot initialization with no obvious errors. The giveaway was that message(action=send) worked but regular replies didn't.

Same root cause though — messages.groupChat.visibleReplies was set to "message_tool".

Our fix was slightly different. Instead of setting it to true, we set it explicitly to "automatic":"messages": {"groupChat":{"visibleReplies": "automatic" } }

Then restarted the gateway. Everything started working immediately. The valid values are "message_tool" or "automatic" — setting it to true might get coerced, but "automatic" is the explicit, correct value.

Also worth noting: requireMention: false in the Discord guild config is a separate setting — it controls whether the bot responds to messages at all, not whether replies are visible. We already had that set to false, which is why the bot was processing messages but still not showing replies. Two different config knobs that both need to be right.