Hi,
Kate here.
Hmmm. That seems very strange :) What you are doing should work. The only thing I can think of that might cause a database to retroactively update itself would be if you:
• Opened the current database and made some changes.
• Then switched to the previous version of the database, having exactly the same name as the new one.
• You've got the Automatic Restore option selected in your Backup & Restore settings. In that case, CatBase might think that you've deliberately reverted to a backup copy and automatically apply the log file to it, thus updating it with the latest amendments - because the name of the backup log file matches the name of BOTH database versions.
See the Backup & Restore Tutorial for detailed info about the automatic backup feature.
Do you rename the backup copy? Maybe name it "Data 2017" and name this year's one "Data 2018" or something like that?
HTH! (Let us know if not)
Kate
CatBase support