As a workaround it helps (often) to add a delay in the KeePass autotype sequence:
{USERNAME}{TAB}{DELAY 600}{PASSWORD}{ENTER}
I also encounter display timing issues in different programs (e.g., Firefox, KeePass, VeraCrypt) that may relate to this issue. Specifically, it takes some time before the typed text or additional menus appear (Firefox, VeryCrypt) and if text is selected, it disappears (KeePass).
Also confirm this bug after update to 18.04.
As a workaround it helps (often) to add a delay in the KeePass autotype sequence:
{USERNAME} {TAB}{DELAY 600}{PASSWORD} {ENTER}
I also encounter display timing issues in different programs (e.g., Firefox, KeePass, VeraCrypt) that may relate to this issue. Specifically, it takes some time before the typed text or additional menus appear (Firefox, VeryCrypt) and if text is selected, it disappears (KeePass).