This is related to why does the cursor freeze in terminals?.
Many terminal emulators (including the native xfce4-terminal) are built with GTK. Unfortunately, GNOME decided that cursor blinking was bad for the environment and by default cursors in GTK applications stop blinking after a short period of time.
The solution to this that has been provided in the past was to install the dconf editor and adjust the value of: /org/gnome/desktop/interface/cursor-blink-timeout
Unfortunately it seems this setting is not honored in Xubuntu 18.04, as the cursor continues to stop blinking after about 10 seconds. (xfce4-terminal, gnome-terminal, lxterminal...)
terminology but that has a whole bunch of dependencies and really doesn't look at all like a conventional terminal emulator. But it does have a cursor that blinks, and keeps blinking.
Is there some trick to getting dconf changes to be recognized? Failing that, can anyone recommend a lightweight terminal with a blinking cursor? (Even xterm would be OK.)