According to THREDDS support:
The issue you're hitting is that minimum temperature and maximum temperature are reported for alternating intervals of 12 hours, so if you request both for a 6 hour period, one won't have any data in range, which is what's causing the exception.
I think that there is some work to improve the behavior here, but in the meantime, this should work instead: If you change the request from a 6 hour interval to just a single time at time=present, it should return the same data, since none of these variables have multiple values within a 6 hour interval.
So instead of time_start and time_end, you can try "time=present".
We need to see what can be done with temperature to prevent this exception in the THREDDS request.