I just purchased the most recent release of Guru Pro and I'm setting up a local test site. This site is very fresh install of Joomla with no other components, templates, or anything.
I added Guru Pro and the dashboard is completely unusable in dark mode. The text is all white and the background is white. Switching to light mode (this is done via the joomla user menu in the top right) fixes this. Joomla by default respects users system preferences, so by default if I have any admin attempt to view the dashboard they will be unable to read anything here's an example of what the settings page looks like:

Once again this is a fresh install of Joomla 5.3.2 and using Guru 6.2.4 with no other templates, components or modules added.