The landlord did not properly serve 3 day notice as required by law. This was defined in the answer, but the landlord was still granted a hearing / trial.
Just now, they have just served another 3-day pay or quit notice (i assume to do it properly) but there is still a hearing set. Thoughts, ideas?
Your question is a bit cryptic. Generally speaking, a demurrer is not permitted in an unlawful detainer lawsuit. Moreover, improper service of the 3 day notice would be raised in the answer but would not be grounds for a demurrer.
The landlord can decide to proceed with the currently pending unlawful detainer trial. Or, the landlord can decide to dismiss the currently pending unlawful detainer and re-file a new complaint for unlawful detainer based upon the newly served 3 day notice to pay or quit.