After the server starts, if no players join before shutdown, the file gets reset to empty.
Since sdmshoponly loads data when players join, shutting down the server without any player connections causes blank data to overwrite the existing file, resulting in data loss.

sdmshopa-neoforge-3.2.3
sdm-core-neoforge-1.21.1-2.1.2
neoforge1.21.1-21.1.209

Reproduction Steps:​​

1. Start the server
2. Ensure no players join
3. Shut down the server
   → The contents of SDMTovarList.sdmwill be reset
   ​​Suggested Fix:​​
   Loading the data once during server startup should resolve this issue.