fix post start sync hang

src/p2pool.cpp

@@ -1464,6 +1464,10 @@ void p2pool::download_block_headers4(uint64_t start_height, uint64_t current_hei
 					// Pre-fetch recent mainchain blocks to populate cache before sidechain sync
 					prefetch_mainchain_blocks(current_height);
 
+					// Retry verification of any unverified sidechain blocks now that mainchain data is available
+					// This catches up the sidechain immediately instead of waiting for the next ZMQ notification
+					m_sideChain->retry_unverified_blocks();
+
 					api_update_network_stats();
 					get_miner_data();