My devices frequently disconnect from my hotspot

There could be a number of things causing your Connectify Hotspot to be unstable. Below are the most common reasons:

Your wireless drivers could be out-of-date.

See here how to update your Wi-Fi drivers: How to Update Your Wireless (Wi-Fi) Driver
Your wireless adapter could be turning itself off to save power.

In Connectify Hotspot, click Settings, then Power, and make sure Keep the adapter awake is on. It is on by default. See How to Disable Adapter Power Management.
Your PC could be going to sleep.

When your PC sleeps, your devices lose their connection until it wakes. On the same Power screen, make sure Allow sleep while running is off (the default), so Windows doesn't put your PC to sleep while the hotspot is on.
There could be wireless interference. There are no natural sources of radio noise in the Wi-Fi band, but there are plenty of man-made sources, like microwave ovens, cordless phones, game consoles, AV equipment, etc.

You might be able to fix your problem simply by moving things around.

If the above suggestions don't help, here's what you could also try:

Switch the way Connectify Hotspot creates the hotspot. Click Settings, then Network, and under Wireless turn Prefer Wi-Fi Direct off, or back on, to see whether your devices stay connected better. If you change it while the hotspot is running, Connectify Hotspot restarts the hotspot. See What is Wi-Fi Direct?
Use a Wi-Fi analyzer app on your phone, or a tool such as inSSIDer on a PC, to view the networks around you and the channels they use. Your Connectify Hotspot will use the same channel as the Wi-Fi network your PC is connected to, so changing the channel settings on your router will also change the channel of your Connectify Hotspot. While your hotspot is sharing, the Wi-Fi channel row of the Connection details card on the Hotspot screen shows which channel it is on. See My hotspot is on 5 GHz: why can't some devices see it?
Try giving your device a fixed IP address. With Hotspot MAX, click Clients, select the device, type a number under Fixed IP address and click Fix. Learn more here: Custom DHCP Ranges and Static IP Addresses.