While my comment is not about Siren it is about connectivity and may be something to look at for those having connectivity issues.
When I got my 536 several months ago I tried the dongle and made connection to my iPhone and iPad no issue like many. Packed the dongle back in the box and not used it since.
However, I have discovered that my router has a 2.4g and 5g radio. I can change which I use by selecting which SSID I use in the device. What I have discovered is my wireless printer can only connect to the 2.4g router radio. If any device I want to print from is on the 5g it is not going to talk to the printer on the 2.4g radio. If I switch the device to the 2.5g then printing works fine.
For the more knowledgeable this lack of data exchange between the two radios in the same router may be common information. Nothing is obviously setup wrong and one of the easy and common checks is can I get to the internet. Because of that I think it easy to believe nothing is wrong with your setup, but the dongle is on one SSID and the device is on the other. I have not checked if in fact this is true for the dongle vs. device, but it is for my HP printer and device.
Those that have a more focused interest and the hardware in place, but poor/erratic or no connectivity can easily check and report back.
Good Luck,
Mike