Migrating from OpenHAB 3.4.4 to 4.0.3 was an exciting yet challenging journey. I encountered an issue with the JDBC PostgreSQL persistence service where the system couldn’t find tables for certain items, despite them existing in the database. This was puzzling, especially after renaming tables to match item names and adjusting configurations multiple times. However, through persistence and community support, I discovered that the issue was related to case sensitivity and table naming conventions in PostgreSQL. Ensuring all table names were in lowercase and correctly configured in the persistence service resolved the problem. This experience highlighted the importance of understanding database specifics and the value of community forums in troubleshooting. I’m now fully operational with OpenHAB 4.0.3, enjoying its enhanced features and stability. A huge thank you to the OpenHAB community for their invaluable assistance!