I have been with Alarm.com and Qolsys for about 4 months now and overall very satisfied with Qolsys. alarm.com on the other hand seems to be hit and miss. There seems to be periods when I enter command for either the panel or the attached z-wave devices and they are virtually instantaneous and other times where it is delayed, often 10-30 seconds. And when delayed the command usually occurs fairly quickly, but the app sits refreshing forever.
It sounds like you are specifically referring to status confirmation signals being returned to Alarm.com from your Qolsys panel. Keep in mind the status confirmation will take some time over cellular. Do you have your panel connected to wifi? If a signal fails over your internet for some reason you will notice it take substantially longer to confirm. 10-30 seconds is pretty common. (10 is actually kind of short.)
I’ve seen this occasionally as well. No real pattern to it but I do also see sporadic “lack of internet connectivity” messages on the system status. When I see that, I do quick cell and wifi dual path tests. Most of the time they’re fine but once in a while they return a “no receipt from Alarm.com” message and then tell me the test was fine and to check with the central station. Seems counter-intuitive.
Might be related?
This is a big reason I fully agree with ADC’s cell service requirement. Wifi/ISP/Router reliability is not on par quite yet. Wifi is not optimal for critical systems or expansive coverage. It does, however, offer blazing speed.
Your test will retry the test signal if the first fails. I do not recall Qolsys specifically calling this out in the wording of the responses.
Next time it happens, I’ll take a screenshot. It’s not often mind you, I’ve seen it maybe two or three times since I installed this and they were all during the same 24 hour period. I didn’t have a loss of connectivity in general (I monitor my connection here from external sources) and the same verbiage was present on both the cell and wifi test protocols. I’m betting a glitch on the ADC side.
I do agree though with not using Wifi or internet in general as the primary means of monitoring a security system. Well obviously or I wouldn’t have made the investment in an actual security system from you guys; way easier and cheaper to just use Canary or its ilk 
I do have it on Wifi with an excellent signal (also panel is less than 15-20 feet from router, although I have seen the panel once in a while say no internet, which is odd since I have rock solid internet with a fat Uverse 45mbps pipe that has been extremely reliable.