We have the same issue, "Computers" and "Users" (under Microsoft Windows Network) only show max 100 entries. We run version 188.8.131.52 of DRS. It started recently. The first report of this behaviour was the very next day after the AD-server (Windows Server 2016) got the WSUS updates for 2019-07 and was rebooted. Lots of people are on vacation at the moment so can't tell for certain if someone noticed this before reboot but the feeling is that it started after.
that is indeed quite unfortunate. However, Dameware is not really used for Computer Inventory. It would be best if you can create a saved host list instead.