I think that you could have your database configured to search for domain matches (which is the default) but on one system, KeePassRPC is unable to determine what the domain name for each website is.
To do this, it needs to download the relevant data from the Public Suffix List service (and store it on disk for later use). If it can never connect to the internet to collect this data, it will have to fall back to hostname matching which in some cases (such as the accounts.google.com example) will result in fewer matches.
If you never want domain matching to work, make sure your database is configured for hostname matching. If you want it to work (even if only on some domains) you’ll need to find out why your system is preventing the download and/or storage of the PSL data.