There are several reasons why nodes might not be synchronizing or could be rejecting your connection. Some nodes might be offline or experiencing technical issues. They might be running outdated or incompatible software versions. Firewalls or network restrictions can block incoming connections. Some nodes are “pruned” and don’t store the full blockchain history, which limits synchronization. Temporary network problems or attacks like DDoS can cause disruptions. Also, some nodes intentionally reject unknown connections for security reasons.