Current Behavior
I can see that the database file is constantly accessed after upgrading to 2.5.0.
The same behavior can be seen if do strace on the pid of the keepassxc process.
This started happening when I updated to 2.5.0 though I've been using the ppa for Ubuntu 18.04 and the last previous version available is 2.3.1
Debug Info
KeePassXC - 2.5.0
Operating system: Ubuntu 18.04
Kernel: 5.0.0-32-generic