Time span between two failed authentication attempts

Is there a timer involved that PAN-OS monitors between the two authentication failure attempts?

As per current design, there is no timer involved that is monitored between the two authentication failure attempts. The PAN-OS only counts the number of consecutive failures and if it matches with the configured value of the Failed Attempts (under the Account Lockout settings) of an Authentication Profile, the account will be locked out for the time as configured in the Lockout Time settings.

Example:

Configuration: Authentication Profile has Failed Attempts=3 and Lockout Time=30 minutes

With the above configuration, the user account will be locked out for 30 minutes after 3 consecutive authentication failures, no matter how much time it takes for three failures or how much time is spent between two failures.

1st authentication fails around 2020-06-25 12:20:48.188
2nd authentication fails around 2020-06-26 12:55:01.574 (after ~24 hrs)
3rd authentication fails around 2020-06-29 12:43:44.819 (after ~3 days) 
The account will be locked out even though all three consecutive failures occurred in a span of ~4 days OR 3 days passed between two failure attempts.