diff --git a/crates/aldabra-dao/src/builder/proposal_create.rs b/crates/aldabra-dao/src/builder/proposal_create.rs
index d569e8c..ca583c6 100644
--- a/crates/aldabra-dao/src/builder/proposal_create.rs
+++ b/crates/aldabra-dao/src/builder/proposal_create.rs
@@ -610,8 +610,20 @@ pub fn build_unsigned_proposal_create(
     // `pvalidateProposalStartingTime` is satisfied because
     // `starting_time_slot ∈ [valid_from, invalid_after - 1]` by
     // construction.
-    staging = staging.valid_from_slot(args.starting_time_slot);
-    staging = staging.invalid_from_slot(args.starting_time_slot + max_width_slots);
+    // 2026-05-08: CENTER `starting_time_slot` inside the validity range
+    // (rather than putting it at the lower bound). Tiny test DAOs run on
+    // a 30-second create_proposal_time_range_max_width, and koios's tip
+    // endpoint lag vs. the actual node can swing ±60s. With
+    // valid_from = starting_time, the window only spans [now, now+30].
+    // If chain is even slightly past `now` when the tx lands, the tx
+    // expires. Centering gives [now-15, now+15] of slack — same width,
+    // same validator-bound, but the chain-now-at-block-time can drift
+    // ±15s without missing the window.
+    let half_width_slots = max_width_slots / 2;
+    let valid_from = args.starting_time_slot.saturating_sub(half_width_slots);
+    let invalid_from = valid_from + max_width_slots;
+    staging = staging.valid_from_slot(valid_from);
+    staging = staging.invalid_from_slot(invalid_from);
 
     let proposer_pkh_arr: [u8; 28] = args
         .proposer_pkh